diff --git a/ros2action/ros2action/api/__init__.py b/ros2action/ros2action/api/__init__.py
index 7f1aba7df..1a2e020fd 100644
--- a/ros2action/ros2action/api/__init__.py
+++ b/ros2action/ros2action/api/__init__.py
@@ -22,6 +22,10 @@
 from rclpy.expand_topic_name import expand_topic_name
 from rclpy.validate_full_topic_name import validate_full_topic_name
 from ros2cli.node.direct import DirectNode
+from rosidl_parser.definition import AbstractNestedType
+from rosidl_parser.definition import NamespacedType
+from rosidl_runtime_py.convert import message_to_yaml
+from rosidl_runtime_py.import_message import import_message_from_namespaced_type
 
 
 def _is_action_status_topic(topic_name, action_name):
@@ -139,3 +143,23 @@ def __call__(self, prefix, parsed_args, **kwargs):
                 if n == action_name:
                     return t
         return []
+
+
+class ActionGoalPrototypeCompleter:
+    """Callable returning an action goal prototype."""
+
+    def __init__(self, *, action_type_key=None):
+        self.action_type_key = action_type_key
+
+    def __call__(self, prefix, parsed_args, **kwargs):
+        full_action_type = getattr(parsed_args, self.action_type_key)
+        try:
+            parts = full_action_type.split('/')
+            package_name = parts[0]
+            interface_type = parts[1]
+            action_type = parts[-1]
+        except LookupError as e:
+            return None
+        action = import_message_from_namespaced_type(
+            AbstractNestedType(NamespacedType([package_name, interface_type], action_type)))
+        return [message_to_yaml(action.Goal())]
diff --git a/ros2action/ros2action/verb/send_goal.py b/ros2action/ros2action/verb/send_goal.py
index 5da03cd10..43e31820e 100644
--- a/ros2action/ros2action/verb/send_goal.py
+++ b/ros2action/ros2action/verb/send_goal.py
@@ -19,6 +19,7 @@
 from rclpy.action import ActionClient
 from ros2action.api import action_name_completer
 from ros2action.api import ActionTypeCompleter
+from ros2action.api import ActionGoalPrototypeCompleter
 from ros2action.verb import VerbExtension
 from ros2cli.node import NODE_NAME_PREFIX
 from rosidl_runtime_py import message_to_yaml
@@ -39,9 +40,10 @@ def add_arguments(self, parser, cli_name):
             'action_type',
             help="Type of the ROS action (e.g. 'example_interfaces/action/Fibonacci')")
         arg.completer = ActionTypeCompleter(action_name_key='action_name')
-        parser.add_argument(
+        arg = parser.add_argument(
             'goal',
             help="Goal request values in YAML format (e.g. '{order: 10}')")
+        arg.completer = ActionGoalPrototypeCompleter(action_type_key='action_type')
         parser.add_argument(
             '-f', '--feedback', action='store_true',
             help='Echo feedback messages for the goal')