diff --git a/lib/keila_web/controllers/segment_controller.ex b/lib/keila_web/controllers/segment_controller.ex
index a2564c84..ab72a2a0 100644
--- a/lib/keila_web/controllers/segment_controller.ex
+++ b/lib/keila_web/controllers/segment_controller.ex
@@ -4,7 +4,9 @@ defmodule KeilaWeb.SegmentController do
   import Ecto.Changeset
   import Phoenix.LiveView.Controller
 
-  plug :authorize when action not in [:index, :new, :create, :delete]
+  @csv_export_chunk_size Application.compile_env!(:keila, :csv_export_chunk_size)
+
+  plug(:authorize when action not in [:index, :new, :create, :delete])
 
   @spec index(Plug.Conn.t(), map()) :: Plug.Conn.t()
   def index(conn, _params) do
@@ -71,6 +73,48 @@ defmodule KeilaWeb.SegmentController do
     |> render("delete.html")
   end
 
+  @spec contacts_export(Plug.Conn.t(), map()) :: Plug.Conn.t()
+  def contacts_export(conn, %{"project_id" => project_id, "id" => segment_id}) do
+    filename = "contacts_#{project_id}_segment_#{segment_id}.csv"
+
+    conn =
+      conn
+      |> put_resp_header("content-disposition", "attachment; filename=\"#{filename}\"")
+      |> put_resp_header("content-type", "text/csv")
+      |> send_chunked(200)
+
+    header =
+      [["Email", "First name", "Last name", "Data", "Status"]]
+      |> NimbleCSV.RFC4180.dump_to_iodata()
+      |> IO.iodata_to_binary()
+
+    {:ok, conn} = chunk(conn, header)
+
+    args = [
+      max_rows: @csv_export_chunk_size,
+      filter: conn.assigns.segment.filter || %{}
+    ]
+
+    Keila.Repo.transaction(fn ->
+      Contacts.stream_project_contacts(project_id, args)
+      |> Stream.map(fn contact ->
+        data = if is_nil(contact.data), do: nil, else: Jason.encode!(contact.data)
+
+        [[contact.email, contact.first_name, contact.last_name, data, contact.status]]
+        |> NimbleCSV.RFC4180.dump_to_iodata()
+        |> IO.iodata_to_binary()
+      end)
+      |> Stream.chunk_every(@csv_export_chunk_size)
+      |> Enum.reduce_while(conn, fn chunk, conn ->
+        case Plug.Conn.chunk(conn, chunk) do
+          {:ok, conn} -> {:cont, conn}
+          {:error, :closed} -> {:halt, conn}
+        end
+      end)
+    end)
+    |> then(fn {:ok, conn} -> conn end)
+  end
+
   defp current_project(conn), do: conn.assigns.current_project
 
   defp authorize(conn, _) do
diff --git a/lib/keila_web/router.ex b/lib/keila_web/router.ex
index e7d2e0cf..b826bfdb 100644
--- a/lib/keila_web/router.ex
+++ b/lib/keila_web/router.ex
@@ -121,6 +121,7 @@ defmodule KeilaWeb.Router do
     get "/projects/:project_id/segments/new", SegmentController, :new
     post "/projects/:project_id/segments", SegmentController, :create
     get "/projects/:project_id/segments/:id", SegmentController, :edit
+    get "/projects/:project_id/segments/:id/contacts_export", SegmentController, :contacts_export
     delete "/projects/:project_id/segments", SegmentController, :delete
 
     get "/projects/:project_id/campaigns", CampaignController, :index
diff --git a/lib/keila_web/templates/segment/edit_live.html.heex b/lib/keila_web/templates/segment/edit_live.html.heex
index d47d0a3e..22daa952 100644
--- a/lib/keila_web/templates/segment/edit_live.html.heex
+++ b/lib/keila_web/templates/segment/edit_live.html.heex
@@ -194,6 +194,12 @@
             <%= pagination_nav(@contacts, phx_click: "change-page") %>
           </div>
         </div>
+        <div>
+          <a href={Routes.segment_path(@socket, :contacts_export, @current_project.id, @segment.id)} class="button">
+            <%= render_icon(:document_add) %>
+            <%= gettext("Export contacts to CSV") %>
+          </a>
+        </div>
       <% end %>
     </div>
   </.form>
diff --git a/test/keila_web/controllers/segment_controller_test.exs b/test/keila_web/controllers/segment_controller_test.exs
index 972d33f5..f33cd6c5 100644
--- a/test/keila_web/controllers/segment_controller_test.exs
+++ b/test/keila_web/controllers/segment_controller_test.exs
@@ -83,4 +83,42 @@ defmodule KeilaWeb.SegmentControllerTest do
       assert segment == Contacts.get_segment(segment.id)
     end
   end
+
+  @tag :segment_controller
+  test "GET /projects/:p_id/export CSV export contacts in multiple chunks", %{conn: conn} do
+    {conn, project} = with_login_and_project(conn)
+
+    segment =
+      insert!(:contacts_segment,
+        project_id: project.id,
+        filter: %{"email" => %{"$like" => "%keila.io"}}
+      )
+
+    insert!(:contact, project_id: project.id, email: "test@example.com")
+
+    contact =
+      insert!(:contact, project_id: project.id, status: :unreachable, email: "test1@keila.io")
+
+    insert!(:contact, project_id: project.id, email: "test2@keila.io")
+    insert!(:contact, project_id: project.id, email: "test3@keila.io")
+    insert!(:contact, project_id: project.id, email: "test4@keila.io")
+    conn = get(conn, Routes.segment_path(conn, :contacts_export, project.id, segment.id))
+
+    assert conn.state == :chunked
+    rows = String.split(response(conn, 200), "\r\n")
+    assert length(rows) == 6
+    assert Enum.at(rows, 1) =~ ~r/,unreachable/
+
+    {_, disposition} = List.keyfind(conn.resp_headers, "content-disposition", 0)
+
+    assert disposition ==
+             "attachment; filename=\"contacts_#{project.id}_segment_#{segment.id}.csv\""
+
+    assert [
+             "Email,First name,Last name,Data,Status",
+             contact_row | _
+           ] = rows
+
+    assert contact_row == "test1@keila.io,#{contact.first_name},#{contact.last_name},,unreachable"
+  end
 end