diff --git a/TESTS/mbed_platform/critical_section/main.cpp b/TESTS/mbed_platform/critical_section/main.cpp
new file mode 100644
index 00000000000..16054310b65
--- /dev/null
+++ b/TESTS/mbed_platform/critical_section/main.cpp
@@ -0,0 +1,230 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2017 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "mbed.h"
+#include "greentea-client/test_env.h"
+#include "unity/unity.h"
+#include "utest/utest.h"
+
+
+using utest::v1::Case;
+
+
+volatile bool callback_called;
+
+void tiemout_callback(void)
+{
+    callback_called = true;
+}
+
+template<int N>
+void critical_section_raii_recursive(Timeout &timeout)
+{
+    static uint32_t depth = 0;
+    CriticalSectionLock cs;
+
+    depth++;
+    TEST_ASSERT_TRUE(core_util_in_critical_section());
+
+    if(depth < N) {
+        critical_section_raii_recursive<N>(timeout);
+    } else {
+        // max depth reached - do the test
+        const us_timestamp_t timeout_time_us = 1;
+        const int wait_time_us = timeout_time_us * 100;
+
+        timeout.attach_us(callback(tiemout_callback), timeout_time_us);
+        wait_us(wait_time_us);
+    }
+    TEST_ASSERT_TRUE(core_util_in_critical_section());
+    TEST_ASSERT_FALSE(callback_called);
+}
+
+
+/** Template for tests
+
+    Test C API of critical section
+    Given a Timeout with callback attached
+    When before critical section
+    Then interrupts are enabled and timeout callback is fired
+    When inside critical section
+    Then interrupts are disabled and timeout callback is blocked
+    When after critical section
+    Then interrupts are enabled and timeout callback is fired
+
+    Test C API of critical section - nested lock
+    Given a Timeout with callback attached
+    When before critical section
+    Then interrupts are enabled and timeout callback is fired
+    When inside nested critical section
+    Then interrupts are disabled and timeout callback is blocked
+    When after critical section
+    Then interrupts are enabled and timeout callback is fired
+ */
+template<int N>
+void test_C_API(void)
+{
+    Timeout timeout;
+    const us_timestamp_t timeout_time_us = 1;
+    const int wait_time_us = timeout_time_us * 100;
+
+    TEST_ASSERT_FALSE(core_util_in_critical_section());
+
+    callback_called = false;
+    timeout.attach_us(callback(tiemout_callback), timeout_time_us);
+    wait_us(wait_time_us);
+    TEST_ASSERT_TRUE(callback_called);
+
+    for(int i = 0; i < N; i++) {
+        core_util_critical_section_enter();
+        TEST_ASSERT_TRUE(core_util_in_critical_section());
+    }
+
+    callback_called = false;
+    timeout.attach_us(callback(tiemout_callback), timeout_time_us);
+    wait_us(wait_time_us);
+    TEST_ASSERT_FALSE(callback_called);
+    TEST_ASSERT_TRUE(core_util_in_critical_section());
+
+    for(int i = 0; i < N - 1; i++) {
+        core_util_critical_section_exit();
+        TEST_ASSERT_TRUE(core_util_in_critical_section());
+        TEST_ASSERT_FALSE(callback_called);
+    }
+
+    core_util_critical_section_exit();
+    TEST_ASSERT_FALSE(core_util_in_critical_section());
+    TEST_ASSERT_TRUE(callback_called);
+}
+
+/** Template for tests
+
+    Test C++ API of critical section constructor/destructor
+    Given a Timeout with callback attached
+    When before critical section
+    Then interrupts are enabled and timeout callback is fired
+    When inside critical section
+    Then interrupts are disabled and timeout callback is blocked
+    When after critical section
+    Then interrupts are enabled and timeout callback is fired
+
+    Test C++ API of critical section constructor/destructor - nested lock
+    Given a Timeout with callback attached
+    When before critical section
+    Then interrupts are enabled and timeout callback is fired
+    When inside nested critical section
+    Then interrupts are disabled and timeout callback is blocked
+    When after critical section
+    Then interrupts are enabled and timeout callback is fired
+ */
+template<int N>
+void test_CPP_API_constructor_destructor(void)
+{
+    Timeout timeout;
+    const us_timestamp_t timeout_time_us = 1;
+    const int wait_time_us = timeout_time_us * 100;
+
+    TEST_ASSERT_FALSE(core_util_in_critical_section());
+
+    callback_called = false;
+    timeout.attach_us(callback(tiemout_callback), timeout_time_us);
+    wait_us(wait_time_us);
+    TEST_ASSERT_TRUE(callback_called);
+
+    callback_called = false;
+    critical_section_raii_recursive<N>(timeout);
+
+    TEST_ASSERT_FALSE(core_util_in_critical_section());
+    TEST_ASSERT_TRUE(callback_called);
+}
+
+/** Template for tests
+
+    Test C++ API of critical section enable/disable
+    Given a Timeout with attached callback
+    When before critical section
+    Then interrupts are enabled and timeout callback is fired
+    When inside critical section
+    Then interrupts are disabled and timeout callback is blocked
+    When after critical section
+    Then interrupts are enabled and timeout callback is fired
+
+    Test C++ API of critical section enable/disable - nested lock
+    Given a Timeout with attached callback
+    When before critical section
+    Then interrupts are enabled and timeout callback is fired
+    When inside nested critical section
+    Then interrupts are disabled and timeout callback is blocked
+    When after critical section
+    Then interrupts are enabled and timeout callback is fired
+ */
+template<int N>
+void test_CPP_API_enable_disable(void)
+{
+    Timeout timeout;
+    const us_timestamp_t timeout_time_us = 1;
+    const int wait_time_us = timeout_time_us * 100;
+
+    TEST_ASSERT_FALSE(core_util_in_critical_section());
+
+    callback_called = false;
+    timeout.attach_us(callback(tiemout_callback), timeout_time_us);
+    wait_us(wait_time_us);
+    TEST_ASSERT_TRUE(callback_called);
+
+    for(int i = 0; i < N; i++) {
+        CriticalSectionLock::enable();
+        TEST_ASSERT_TRUE(core_util_in_critical_section());
+    }
+
+    callback_called = false;
+    timeout.attach_us(callback(tiemout_callback), timeout_time_us);
+    wait_us(wait_time_us);
+    TEST_ASSERT_FALSE(callback_called);
+    TEST_ASSERT_TRUE(core_util_in_critical_section());
+
+    for(int i = 0; i < N - 1; i++) {
+        CriticalSectionLock::disable();
+        TEST_ASSERT_TRUE(core_util_in_critical_section());
+        TEST_ASSERT_FALSE(callback_called);
+    }
+
+    CriticalSectionLock::disable();
+    TEST_ASSERT_FALSE(core_util_in_critical_section());
+    TEST_ASSERT_TRUE(callback_called);
+}
+
+
+utest::v1::status_t test_setup(const size_t number_of_cases)
+{
+    GREENTEA_SETUP(10, "default_auto");
+    return utest::v1::verbose_test_setup_handler(number_of_cases);
+}
+
+Case cases[] = {
+    Case("Test critical section C API", test_C_API<1>),
+    Case("Test critical section C API nested lock", test_C_API<10>),
+    Case("Test critical section C++ API constructor/destructor", test_CPP_API_constructor_destructor<1>),
+    Case("Test critical section C++ API constructor/destructor nested lock", test_CPP_API_constructor_destructor<10>),
+    Case("Test critical section C++ API enable/disable", test_CPP_API_enable_disable<1>),
+    Case("Test critical section C++ API enable/disable nested lock", test_CPP_API_enable_disable<10>)
+};
+
+utest::v1::Specification specification(test_setup, cases);
+
+int main()
+{
+    return !utest::v1::Harness::run(specification);
+}