Nowadays, Real-Time Operating Systems (RTOSs) are often adopted in order to simplify the design of safety-critical applications. However, real-time embedded systems are sensitive to transient faults that can affect the system causing scheduling dysfunctions and consequently changing the correct system behavior. In this context, we propose a new hardware-based approach able to detect faults that change the tasks' execution time and/or the tasks' execution flow in embedded systems based on RTOS. To demonstrate the effectiveness and benefits of using the proposed approach, we implemented a hardware prototype named Hardware-Scheduler (Hw-S) that provides real-time monitoring of the Plasma Microprocessor's RTOS in order to detect the above mentioned types of faults. The Hw-S has been evaluated in terms of the introduced area overhead and fault detection capability. © 2009 IEEE.