diff --git a/src/Matcher/Pattern/Expander/Count.php b/src/Matcher/Pattern/Expander/Count.php
new file mode 100644
index 00000000..1698a417
--- /dev/null
+++ b/src/Matcher/Pattern/Expander/Count.php
@@ -0,0 +1,54 @@
+<?php
+
+namespace Coduo\PHPMatcher\Matcher\Pattern\Expander;
+
+use Coduo\PHPMatcher\Matcher\Pattern\PatternExpander;
+use Coduo\ToString\StringConverter;
+
+final class Count implements PatternExpander
+{
+    /**
+     * @var null|string
+     */
+    private $error;
+
+    /**
+     * @var
+     */
+    private $value;
+
+    /**
+     * @param $value
+     */
+    public function __construct($value)
+    {
+        $this->value = $value;
+    }
+
+    /**
+     * @param $value
+     * @return boolean
+     */
+    public function match($value)
+    {
+        if (!is_array($value)) {
+            $this->error = sprintf("Count expander require \"array\", got \"%s\".", new StringConverter($value));
+            return false;
+        }
+
+        if (count($value) !== $this->value) {
+            $this->error = sprintf("Expected count of %s is %s.", new StringConverter($value), new StringConverter($this->value));
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * @return string|null
+     */
+    public function getError()
+    {
+        return $this->error;
+    }
+}
diff --git a/src/Parser/ExpanderInitializer.php b/src/Parser/ExpanderInitializer.php
index bdc4db49..9f21bcd7 100644
--- a/src/Parser/ExpanderInitializer.php
+++ b/src/Parser/ExpanderInitializer.php
@@ -25,6 +25,7 @@ final class ExpanderInitializer
         "lowerThan" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\LowerThan",
         "greaterThan" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\GreaterThan",
         "inArray" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\InArray",
+        "count" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\Count",
         "contains" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\Contains",
         "matchRegex" => "Coduo\\PHPMatcher\\Matcher\\Pattern\\Expander\\MatchRegex",
 
diff --git a/tests/Matcher/Pattern/Expander/CountTest.php b/tests/Matcher/Pattern/Expander/CountTest.php
new file mode 100644
index 00000000..cb99fd22
--- /dev/null
+++ b/tests/Matcher/Pattern/Expander/CountTest.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace Coduo\PHPMatcher\Tests\Matcher\Pattern\Expander;
+
+use Coduo\PHPMatcher\Matcher;
+use Coduo\PHPMatcher\Matcher\Pattern\Expander\Count;
+
+class CountTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @dataProvider examplesProvider
+     */
+    public function test_matching_values($needle, $haystack, $expectedResult)
+    {
+        $expander = new Count($needle);
+        $this->assertEquals($expectedResult, $expander->match($haystack));
+    }
+
+    public static function examplesProvider()
+    {
+        return array(
+            array(1, array("ipsum"), true),
+            array(2, array("foo", 1), true),
+        );
+    }
+
+    /**
+     * @dataProvider invalidCasesProvider
+     */
+    public function test_error_when_matching_fail($boundary, $value, $errorMessage)
+    {
+        $expander = new Count($boundary);
+        $this->assertFalse($expander->match($value));
+        $this->assertEquals($errorMessage, $expander->getError());
+    }
+
+    public static function invalidCasesProvider()
+    {
+        return array(
+            array(2, array(1, 2, 3), "Expected count of Array(3) is 2."),
+            array(2, new \DateTime(), "Count expander require \"array\", got \"\\DateTime\"."),
+        );
+    }
+}
diff --git a/tests/MatcherTest.php b/tests/MatcherTest.php
index 83ab40f2..d550cf6d 100644
--- a/tests/MatcherTest.php
+++ b/tests/MatcherTest.php
@@ -244,6 +244,8 @@ public static function expanderExamples()
             array(array("foo", "bar"), "@array@.inArray(\"bar\")", true),
             array(array(), "@array@.isEmpty()", true),
             array(array('foo'), "@array@.isEmpty()", false),
+            array(array(1, 2, 3), "@array@.count(3)", true),
+            array(array(1, 2, 3), "@array@.count(4)", false),
             array("lorem ipsum", "@string@.oneOf(contains(\"lorem\"), contains(\"test\"))", true),
             array("lorem ipsum", "@string@.oneOf(contains(\"lorem\"), contains(\"test\")).endsWith(\"ipsum\")", true),
             array("lorem ipsum", "@string@.matchRegex(\"/^lorem \\w+$/\")", true),