diff --git a/ros2cli_test_interfaces/CMakeLists.txt b/ros2cli_test_interfaces/CMakeLists.txt
index b3c905927..f7e2008c8 100644
--- a/ros2cli_test_interfaces/CMakeLists.txt
+++ b/ros2cli_test_interfaces/CMakeLists.txt
@@ -10,7 +10,9 @@ find_package(rosidl_default_generators REQUIRED)
 
 rosidl_generate_interfaces(${PROJECT_NAME}
   "action/ShortVariedMultiNested.action"
+  "msg/IdlOnly.idl"
   "msg/ShortVaried.msg"
+  "msg/ShortVariedIdlNested.msg"
   "msg/ShortVariedMultiNested.msg"
   "msg/ShortVariedNested.msg"
   "srv/ShortVariedMultiNested.srv"
diff --git a/ros2cli_test_interfaces/msg/IdlOnly.idl b/ros2cli_test_interfaces/msg/IdlOnly.idl
new file mode 100644
index 000000000..e1ea063a1
--- /dev/null
+++ b/ros2cli_test_interfaces/msg/IdlOnly.idl
@@ -0,0 +1,7 @@
+module ros2cli_test_interfaces {
+  module msg {
+    struct IdlOnly {
+      uint32 value;
+    };
+  };
+};
diff --git a/ros2cli_test_interfaces/msg/ShortVariedIdlNested.msg b/ros2cli_test_interfaces/msg/ShortVariedIdlNested.msg
new file mode 100644
index 000000000..30b45757a
--- /dev/null
+++ b/ros2cli_test_interfaces/msg/ShortVariedIdlNested.msg
@@ -0,0 +1 @@
+IdlOnly idl_only
diff --git a/ros2interface/ros2interface/verb/show.py b/ros2interface/ros2interface/verb/show.py
index aec3eb641..94aeb7d09 100644
--- a/ros2interface/ros2interface/verb/show.py
+++ b/ros2interface/ros2interface/verb/show.py
@@ -104,7 +104,10 @@ def _is_nested(self) -> bool:
             return False
 
 
-def _get_interface_lines(interface_identifier: str) -> typing.Iterable[InterfaceTextLine]:
+def _get_interface_lines(
+    interface_identifier: str,
+    file_path: str,
+) -> typing.Iterable[InterfaceTextLine]:
     parts: typing.List[str] = interface_identifier.split('/')
     if len(parts) != 3:
         raise ValueError(
@@ -112,7 +115,6 @@ def _get_interface_lines(interface_identifier: str) -> typing.Iterable[Interface
         )
     pkg_name, _, msg_name = parts
 
-    file_path = get_interface_path(interface_identifier)
     with open(file_path) as file_handler:
         for line in file_handler:
             yield InterfaceTextLine(
@@ -147,7 +149,18 @@ def _show_interface(
     is_show_nested_comments: bool = False,
     indent_level: int = 0
 ):
-    for line in _get_interface_lines(interface_identifier):
+    file_path = get_interface_path(interface_identifier)
+    if file_path.endswith('.idl'):
+        with open(file_path) as file_handler:
+            content = file_handler.read()
+        indent_string = indent_level * '\t'
+        for line in content.splitlines():
+            print(f'{indent_string}{line}' if line else '')
+        if not content or not content.endswith('\n'):
+            print()
+        return
+
+    for line in _get_interface_lines(interface_identifier, file_path):
 
         _print_interface_line(
             line, is_show_comments=is_show_comments, indent_level=indent_level)
diff --git a/ros2interface/test/test_cli.py b/ros2interface/test/test_cli.py
index cc654b48c..047283440 100644
--- a/ros2interface/test/test_cli.py
+++ b/ros2interface/test/test_cli.py
@@ -302,6 +302,47 @@ def test_show_message(self):
             strict=True
         )
 
+    def test_show_idl_message(self):
+        with self.launch_interface_command(
+            arguments=['show', 'ros2cli_test_interfaces/msg/IdlOnly']
+        ) as interface_command:
+            assert interface_command.wait_for_shutdown(timeout=2)
+        assert interface_command.exit_code == launch_testing.asserts.EXIT_OK
+        assert launch_testing.tools.expect_output(
+            expected_lines=[
+                'module ros2cli_test_interfaces {',
+                '  module msg {',
+                '    struct IdlOnly {',
+                '      uint32 value;',
+                '    };',
+                '  };',
+                '};',
+            ],
+            text=interface_command.output,
+            strict=True
+        )
+
+    def test_show_message_with_idl_nested_type(self):
+        with self.launch_interface_command(
+            arguments=['show', 'ros2cli_test_interfaces/msg/ShortVariedIdlNested']
+        ) as interface_command:
+            assert interface_command.wait_for_shutdown(timeout=2)
+        assert interface_command.exit_code == launch_testing.asserts.EXIT_OK
+        assert launch_testing.tools.expect_output(
+            expected_lines=[
+                'IdlOnly idl_only',
+                '\tmodule ros2cli_test_interfaces {',
+                '\t  module msg {',
+                '\t    struct IdlOnly {',
+                '\t      uint32 value;',
+                '\t    };',
+                '\t  };',
+                '\t};',
+            ],
+            text=interface_command.output,
+            strict=True
+        )
+
     def test_show_message_with_all_comments(self):
         with self.launch_interface_command(
             arguments=[