diff --git a/common/changes/@typespec/versioning/versioning-OpParams_2023-11-10-16-19.json b/common/changes/@typespec/versioning/versioning-OpParams_2023-11-10-16-19.json
new file mode 100644
index 0000000000..885c527c79
--- /dev/null
+++ b/common/changes/@typespec/versioning/versioning-OpParams_2023-11-10-16-19.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@typespec/versioning",
+      "comment": "Fix issue where the version compatability of parameters in operation signatures was not checked.",
+      "type": "none"
+    }
+  ],
+  "packageName": "@typespec/versioning"
+}
\ No newline at end of file
diff --git a/packages/versioning/src/lib.ts b/packages/versioning/src/lib.ts
index 8d2a6628d1..9a4d74df89 100644
--- a/packages/versioning/src/lib.ts
+++ b/packages/versioning/src/lib.ts
@@ -67,10 +67,10 @@ const libDef = {
       severity: "error",
       messages: {
         default: paramMessage`'${"sourceName"}' is referencing versioned type '${"targetName"}' but is not versioned itself.`,
-        addedAfter: paramMessage`'${"sourceName"}' was added on version '${"sourceAddedOn"}' but referencing type '${"targetName"}' added in version '${"targetAddedOn"}'.`,
-        dependentAddedAfter: paramMessage`'${"sourceName"}' was added on version '${"sourceAddedOn"}' but contains type '${"targetName"}' added in version '${"targetAddedOn"}'.`,
-        removedBefore: paramMessage`'${"sourceName"}' was removed on version '${"sourceRemovedOn"}' but referencing type '${"targetName"}' removed in version '${"targetRemovedOn"}'.`,
-        dependentRemovedBefore: paramMessage`'${"sourceName"}' was removed on version '${"sourceRemovedOn"}' but contains type '${"targetName"}' removed in version '${"targetRemovedOn"}'.`,
+        addedAfter: paramMessage`'${"sourceName"}' was added in version '${"sourceAddedOn"}' but referencing type '${"targetName"}' added in version '${"targetAddedOn"}'.`,
+        dependentAddedAfter: paramMessage`'${"sourceName"}' was added in version '${"sourceAddedOn"}' but contains type '${"targetName"}' added in version '${"targetAddedOn"}'.`,
+        removedBefore: paramMessage`'${"sourceName"}' was removed in version '${"sourceRemovedOn"}' but referencing type '${"targetName"}' removed in version '${"targetRemovedOn"}'.`,
+        dependentRemovedBefore: paramMessage`'${"sourceName"}' was removed in version '${"sourceRemovedOn"}' but contains type '${"targetName"}' removed in version '${"targetRemovedOn"}'.`,
         versionedDependencyAddedAfter: paramMessage`'${"sourceName"}' is referencing type '${"targetName"}' added in version '${"targetAddedOn"}' but version used is ${"dependencyVersion"}.`,
         versionedDependencyRemovedBefore: paramMessage`'${"sourceName"}' is referencing type '${"targetName"}' removed in version '${"targetAddedOn"}' but version used is ${"dependencyVersion"}.`,
         doesNotExist: paramMessage`'${"sourceName"}' is referencing type '${"targetName"}' which does not exist in version '${"version"}'.`,
diff --git a/packages/versioning/src/validate.ts b/packages/versioning/src/validate.ts
index eb79e45db0..5748c727c1 100644
--- a/packages/versioning/src/validate.ts
+++ b/packages/versioning/src/validate.ts
@@ -93,10 +93,11 @@ export function $onValidate(program: Program) {
         addDependency(namespace, op.returnType);
 
         if (op.interface) {
-          // Validate model -> property have correct versioning
           validateTargetVersionCompatible(program, op.interface, op, { isTargetADependent: true });
         }
-
+        for (const prop of op.parameters.properties.values()) {
+          validateReference(program, op, prop.type);
+        }
         validateReference(program, op, op.returnType);
       },
       interface: (iface) => {
diff --git a/packages/versioning/test/incompatible-versioning.test.ts b/packages/versioning/test/incompatible-versioning.test.ts
index 578a16b0c7..84a5172c7a 100644
--- a/packages/versioning/test/incompatible-versioning.test.ts
+++ b/packages/versioning/test/incompatible-versioning.test.ts
@@ -102,6 +102,70 @@ describe("versioning: validate incompatible references", () => {
     });
   });
 
+  describe("operation", () => {
+    it("emit diagnostic when unversioned op has a versioned model as a parameter", async () => {
+      const diagnostics = await runner.diagnose(`
+        @added(Versions.v2)
+        model Foo {}
+
+        op test(param: Foo): void;
+      `);
+      expectDiagnostics(diagnostics, {
+        code: "@typespec/versioning/incompatible-versioned-reference",
+        message:
+          "'TestService.test' is referencing versioned type 'TestService.Foo' but is not versioned itself.",
+      });
+    });
+
+    it("emit diagnostic when unversioned op based on a template has a versioned model as a parameter", async () => {
+      const diagnostics = await runner.diagnose(`
+        @added(Versions.v2)
+        model Foo {}
+
+        op Template<T>(param: T): void;
+
+        op test is Template<Foo>;
+      `);
+      expectDiagnostics(diagnostics, {
+        code: "@typespec/versioning/incompatible-versioned-reference",
+        message:
+          "'TestService.test' is referencing versioned type 'TestService.Foo' but is not versioned itself.",
+      });
+    });
+
+    it("emit diagnostic when when op was added before parameter", async () => {
+      const diagnostics = await runner.diagnose(`
+        @added(Versions.v2)
+        model Foo {}
+
+        @added(Versions.v1)
+        op test(param: Foo): void;
+      `);
+      expectDiagnostics(diagnostics, {
+        code: "@typespec/versioning/incompatible-versioned-reference",
+        message:
+          "'TestService.test' was added in version 'v1' but referencing type 'TestService.Foo' added in version 'v2'.",
+      });
+    });
+
+    it("emit diagnostic when op based on a template was added before parameter", async () => {
+      const diagnostics = await runner.diagnose(`
+        @added(Versions.v2)
+        model Foo {}
+
+        op Template<T>(param: T): void;
+
+        @added(Versions.v1)
+        op test is Template<Foo>;
+      `);
+      expectDiagnostics(diagnostics, {
+        code: "@typespec/versioning/incompatible-versioned-reference",
+        message:
+          "'TestService.test' was added in version 'v1' but referencing type 'TestService.Foo' added in version 'v2'.",
+      });
+    });
+  });
+
   describe("operation return type", () => {
     it("emit diagnostic when unversioned op is returning versioned model", async () => {
       const diagnostics = await runner.diagnose(`
@@ -128,7 +192,7 @@ describe("versioning: validate incompatible references", () => {
       expectDiagnostics(diagnostics, {
         code: "@typespec/versioning/incompatible-versioned-reference",
         message:
-          "'TestService.test' was added on version 'v2' but referencing type 'TestService.Foo' added in version 'v3'.",
+          "'TestService.test' was added in version 'v2' but referencing type 'TestService.Foo' added in version 'v3'.",
       });
     });
 
@@ -143,7 +207,7 @@ describe("versioning: validate incompatible references", () => {
       expectDiagnostics(diagnostics, {
         code: "@typespec/versioning/incompatible-versioned-reference",
         message:
-          "'TestService.test' was removed on version 'v3' but referencing type 'TestService.Foo' removed in version 'v2'.",
+          "'TestService.test' was removed in version 'v3' but referencing type 'TestService.Foo' removed in version 'v2'.",
       });
     });
 
@@ -206,7 +270,7 @@ describe("versioning: validate incompatible references", () => {
       expectDiagnostics(diagnostics, {
         code: "@typespec/versioning/incompatible-versioned-reference",
         message:
-          "'TestService.Bar.foo' was added on version 'v2' but referencing type 'TestService.Foo' added in version 'v3'.",
+          "'TestService.Bar.foo' was added in version 'v2' but referencing type 'TestService.Foo' added in version 'v3'.",
       });
     });
 
@@ -223,7 +287,7 @@ describe("versioning: validate incompatible references", () => {
       expectDiagnostics(diagnostics, {
         code: "@typespec/versioning/incompatible-versioned-reference",
         message:
-          "'TestService.Bar.foo' was removed on version 'v3' but referencing type 'TestService.Foo' removed in version 'v2'.",
+          "'TestService.Bar.foo' was removed in version 'v3' but referencing type 'TestService.Foo' removed in version 'v2'.",
       });
     });
 
@@ -328,7 +392,7 @@ describe("versioning: validate incompatible references", () => {
       expectDiagnostics(diagnostics, {
         code: "@typespec/versioning/incompatible-versioned-reference",
         message:
-          "'TestService.Bar' was added on version 'v3' but contains type 'TestService.Bar.foo' added in version 'v2'.",
+          "'TestService.Bar' was added in version 'v3' but contains type 'TestService.Bar.foo' added in version 'v2'.",
       });
     });
 
@@ -343,7 +407,7 @@ describe("versioning: validate incompatible references", () => {
       expectDiagnostics(diagnostics, {
         code: "@typespec/versioning/incompatible-versioned-reference",
         message:
-          "'TestService.Bar' was removed on version 'v2' but contains type 'TestService.Bar.foo' removed in version 'v3'.",
+          "'TestService.Bar' was removed in version 'v2' but contains type 'TestService.Bar.foo' removed in version 'v3'.",
       });
     });
 
@@ -404,7 +468,7 @@ describe("versioning: validate incompatible references", () => {
           "'TestService.Bar.foo' is referencing versioned type 'TestService.Versioned' but is not versioned itself.",
       });
     });
-    it("emit diagnostic when using versioned union variant in non versioned operation return type", async () => {
+    it("emit diagnostic when using versioned union variant in nin versioned operation return type", async () => {
       const diagnostics = await runner.diagnose(`
         @added(Versions.v2)
         model Versioned {}
@@ -417,7 +481,7 @@ describe("versioning: validate incompatible references", () => {
       });
     });
 
-    it("emit diagnostic when using versioned array element in non versioned operation return type", async () => {
+    it("emit diagnostic when using versioned array element in nin versioned operation return type", async () => {
       const diagnostics = await runner.diagnose(`
         @added(Versions.v2)
         model Versioned {}
@@ -430,7 +494,7 @@ describe("versioning: validate incompatible references", () => {
       });
     });
 
-    it("emit diagnostic when using versioned tuple element in non versioned operation return type", async () => {
+    it("emit diagnostic when using versioned tuple element in nin versioned operation return type", async () => {
       const diagnostics = await runner.diagnose(`
         @added(Versions.v2)
         model Versioned {}
@@ -466,7 +530,7 @@ describe("versioning: validate incompatible references", () => {
       expectDiagnostics(diagnostics, {
         code: "@typespec/versioning/incompatible-versioned-reference",
         message:
-          "'TestService.Bar' was added on version 'v3' but contains type 'TestService.foo' added in version 'v2'.",
+          "'TestService.Bar' was added in version 'v3' but contains type 'TestService.foo' added in version 'v2'.",
       });
     });
 
@@ -481,7 +545,7 @@ describe("versioning: validate incompatible references", () => {
       expectDiagnostics(diagnostics, {
         code: "@typespec/versioning/incompatible-versioned-reference",
         message:
-          "'TestService.Bar' was removed on version 'v2' but contains type 'TestService.foo' removed in version 'v3'.",
+          "'TestService.Bar' was removed in version 'v2' but contains type 'TestService.foo' removed in version 'v3'.",
       });
     });
 
@@ -544,7 +608,7 @@ describe("versioning: validate incompatible references", () => {
       expectDiagnostics(diagnostics, {
         code: "@typespec/versioning/incompatible-versioned-reference",
         message:
-          "'TestService.WidgetService' was added on version 'v1' but referencing type 'TestService.Widget' added in version 'v2'.",
+          "'TestService.WidgetService' was added in version 'v1' but referencing type 'TestService.Widget' added in version 'v2'.",
       });
     });
 
@@ -601,7 +665,7 @@ describe("versioning: validate incompatible references", () => {
       expectDiagnostics(diagnostics, {
         code: "@typespec/versioning/incompatible-versioned-reference",
         message:
-          "'TestService.test' was added on version 'v1' but referencing type 'VersionedLib.Foo' added in version 'v3'.",
+          "'TestService.test' was added in version 'v1' but referencing type 'VersionedLib.Foo' added in version 'v3'.",
       });
     });