diff --git a/CHANGELOG.md b/CHANGELOG.md
index 66e7f104..8f59ee3a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Add support for `without_project_bots` in `Users::all`
 * Add support for date filters and `finished_at` ordering in `Deployments::all`
 * Add support for listing merge requests associated with a deployment
+* Add support for `with_custom_attributes` and `with_projects` in `Groups::show`
 
 
 ## [12.0.0] - 2025-02-23
diff --git a/src/Api/Groups.php b/src/Api/Groups.php
index f592422d..5248e36e 100644
--- a/src/Api/Groups.php
+++ b/src/Api/Groups.php
@@ -68,9 +68,30 @@ public function all(array $parameters = []): mixed
         return $this->get('groups', $resolver->resolve($parameters));
     }
 
-    public function show(int|string $id): mixed
+    /**
+     * @param array $parameters {
+     *
+     *     @var bool $with_custom_attributes include custom attributes in response
+     *     @var bool $with_projects          Include details from projects that belong to the group.
+     * }
+     */
+    public function show(int|string $id, array $parameters = []): mixed
     {
-        return $this->get('groups/'.self::encodePath($id));
+        $resolver = $this->createOptionsResolver();
+        $booleanNormalizer = function (Options $resolver, $value): string {
+            return $value ? 'true' : 'false';
+        };
+
+        $resolver->setDefined('with_custom_attributes')
+            ->setAllowedTypes('with_custom_attributes', 'bool')
+            ->setNormalizer('with_custom_attributes', $booleanNormalizer)
+        ;
+        $resolver->setDefined('with_projects')
+            ->setAllowedTypes('with_projects', 'bool')
+            ->setNormalizer('with_projects', $booleanNormalizer)
+        ;
+
+        return $this->get('groups/'.self::encodePath($id), $resolver->resolve($parameters));
     }
 
     public function create(string $name, string $path, ?string $description = null, string $visibility = 'private', ?bool $lfs_enabled = null, ?bool $request_access_enabled = null, ?int $parent_id = null, ?int $shared_runners_minutes_limit = null): mixed
diff --git a/tests/Api/GroupsTest.php b/tests/Api/GroupsTest.php
index 05a54e03..3bd2c7df 100644
--- a/tests/Api/GroupsTest.php
+++ b/tests/Api/GroupsTest.php
@@ -143,6 +143,22 @@ public function shouldShowGroup(): void
         $this->assertEquals($expectedArray, $api->show(1));
     }
 
+    #[Test]
+    public function shouldShowGroupWithAdditionalParameters(): void
+    {
+        $expectedArray = ['id' => 1, 'name' => 'A group'];
+        $parameters = ['with_custom_attributes' => true, 'with_projects' => false];
+
+        $api = $this->getApiMock();
+        $api->expects($this->once())
+            ->method('get')
+            ->with('groups/1', ['with_custom_attributes' => 'true', 'with_projects' => 'false'])
+            ->willReturn($expectedArray)
+        ;
+
+        $this->assertEquals($expectedArray, $api->show(1, $parameters));
+    }
+
     #[Test]
     public function shouldCreateGroup(): void
     {