diff --git a/generator/integration_tests/golden/v1/golden_kitchen_sink_client.h b/generator/integration_tests/golden/v1/golden_kitchen_sink_client.h
index a62131b8c8d5f..8976243806b6d 100644
--- a/generator/integration_tests/golden/v1/golden_kitchen_sink_client.h
+++ b/generator/integration_tests/golden/v1/golden_kitchen_sink_client.h
@@ -38,6 +38,8 @@ GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
 ///
 /// GoldenKitchenSinkClient
 ///
+/// This client uses GoldenKitchenSink version test-api-version.
+///
 /// @par Equality
 ///
 /// Instances of this class created via copy-construction or copy-assignment
diff --git a/generator/internal/format_class_comments.cc b/generator/internal/format_class_comments.cc
index c2908d388cee1..5ad6e1659e535 100644
--- a/generator/internal/format_class_comments.cc
+++ b/generator/internal/format_class_comments.cc
@@ -18,6 +18,7 @@
 #include "google/cloud/internal/absl_str_replace_quiet.h"
 #include "google/cloud/log.h"
 #include "absl/strings/strip.h"
+#include <google/api/client.pb.h>
 
 namespace google {
 namespace cloud {
@@ -78,6 +79,12 @@ std::string FormatClassCommentsFromServiceComments(
          {service.name(), service_name}});
   }
 
+  auto api_version = service.options().GetExtension(google::api::api_version);
+  if (!api_version.empty()) {
+    absl::StrAppend(&formatted_comments, "\n///\n/// This client uses ",
+                    service_name, " version ", api_version, ".");
+  }
+
   auto const references =
       ResolveCommentReferences(formatted_comments, *service.file()->pool());
   auto trailer = std::string{};