diff --git a/library/Exceptions/SubdivisionCode/GmSubdivisionCodeException.php b/library/Exceptions/SubdivisionCode/GmSubdivisionCodeException.php
new file mode 100644
index 00000000..d707a513
--- /dev/null
+++ b/library/Exceptions/SubdivisionCode/GmSubdivisionCodeException.php
@@ -0,0 +1,31 @@
+<?php
+
+/*
+ * This file is part of Respect/Validation.
+ *
+ * (c) Alexandre Gomes Gaigalas <alexandre@gaigalas.net>
+ *
+ * For the full copyright and license information, please view the "LICENSE.md"
+ * file that was distributed with this source code.
+ */
+
+namespace Respect\Validation\Exceptions\SubdivisionCode;
+
+use Respect\Validation\Exceptions\SubdivisionCodeException;
+
+/**
+ * Exception class for Gambia subdivision code.
+ *
+ * ISO 3166-1 alpha-2: GM
+ */
+class GmSubdivisionCodeException extends SubdivisionCodeException
+{
+    public static $defaultTemplates = array(
+        self::MODE_DEFAULT => array(
+            self::STANDARD => '{{name}} must be a subdivision code of Gambia',
+        ),
+        self::MODE_NEGATIVE => array(
+            self::STANDARD => '{{name}} must not be a subdivision code of Gambia',
+        ),
+    );
+}
diff --git a/library/Rules/SubdivisionCode/GmSubdivisionCode.php b/library/Rules/SubdivisionCode/GmSubdivisionCode.php
new file mode 100644
index 00000000..941db36c
--- /dev/null
+++ b/library/Rules/SubdivisionCode/GmSubdivisionCode.php
@@ -0,0 +1,35 @@
+<?php
+
+/*
+ * This file is part of Respect/Validation.
+ *
+ * (c) Alexandre Gomes Gaigalas <alexandre@gaigalas.net>
+ *
+ * For the full copyright and license information, please view the "LICENSE.md"
+ * file that was distributed with this source code.
+ */
+
+namespace Respect\Validation\Rules\SubdivisionCode;
+
+use Respect\Validation\Rules\AbstractSearcher;
+
+/**
+ * Validator for Gambia subdivision code.
+ *
+ * ISO 3166-1 alpha-2: GM
+ *
+ * @link http://www.geonames.org/GM/administrative-division-gambia.html
+ */
+class GmSubdivisionCode extends AbstractSearcher
+{
+    public $haystack = array(
+        'B', // Banjul
+        'L', // Lower River
+        'M', // Central River
+        'N', // North Bank
+        'U', // Upper River
+        'W', // Western
+    );
+
+    public $compareIdentical = true;
+}