diff --git a/rclpy/src/rclpy/_rclpy.c b/rclpy/src/rclpy/_rclpy.c
index 548974ddb..835085281 100644
--- a/rclpy/src/rclpy/_rclpy.c
+++ b/rclpy/src/rclpy/_rclpy.c
@@ -558,16 +558,35 @@ rclpy_init(PyObject * Py_UNUSED(self), PyObject * args)
   if (have_args) {
     rcl_init_options_t init_options = rcl_get_zero_initialized_init_options();
     rcl_ret_t ret = rcl_init_options_init(&init_options, allocator);
-    if (RCL_RET_OK != ret) {
-      PyErr_Format(
-        RCLError, "Failed to initialize init_options: %s", rcl_get_error_string().str);
-      rcl_reset_error();
-    } else {
+    if (RCL_RET_OK == ret) {
       ret = rcl_init(num_args, arg_values, &init_options, context);
-      if (ret != RCL_RET_OK) {
-        PyErr_Format(RCLError, "Failed to init: %s", rcl_get_error_string().str);
+      if (RCL_RET_OK == ret) {
+        int unparsed_ros_args_count =
+          rcl_arguments_get_count_unparsed_ros(&context->global_arguments);
+        if (unparsed_ros_args_count > 0) {
+          int * unparsed_ros_args_indices = NULL;
+          ret = rcl_arguments_get_unparsed_ros(
+            &context->global_arguments, allocator, &unparsed_ros_args_indices);
+          if (RCL_RET_OK == ret) {
+            _rclpy_raise_unknown_ros_args(
+              pyargs, unparsed_ros_args_indices, unparsed_ros_args_count);
+            allocator.deallocate(unparsed_ros_args_indices, allocator.state);
+          } else {
+            PyErr_Format(
+              PyExc_RuntimeError,
+              "Failed to get unparsed ROS arguments: %s",
+              rcl_get_error_string().str);
+            rcl_reset_error();
+          }
+        }
+      } else {
+        PyErr_Format(PyExc_RuntimeError, "Failed to init: %s", rcl_get_error_string().str);
         rcl_reset_error();
       }
+    } else {
+      PyErr_Format(
+        PyExc_RuntimeError, "Failed to initialize init_options: %s", rcl_get_error_string().str);
+      rcl_reset_error();
     }
   }
   if (NULL != arg_values) {
diff --git a/rclpy/test/test_init_shutdown.py b/rclpy/test/test_init_shutdown.py
index 0ebeeedbe..b310d9fd4 100644
--- a/rclpy/test/test_init_shutdown.py
+++ b/rclpy/test/test_init_shutdown.py
@@ -23,6 +23,15 @@ def test_init():
     rclpy.shutdown(context=context)
 
 
+def test_init_with_unknown_ros_args():
+    from rclpy.impl.implementation_singleton import rclpy_implementation as _rclpy
+
+    context = rclpy.context.Context()
+    unknown_ros_args_error_pattern = r'Found unknown ROS arguments:.*\[\'unknown\'\]'
+    with pytest.raises(_rclpy.UnknownROSArgsError, match=unknown_ros_args_error_pattern):
+        rclpy.init(context=context, args=['--ros-args', 'unknown'])
+
+
 def test_init_with_non_utf8_arguments():
     context = rclpy.context.Context()
     # Embed non decodable characters e.g. due to