Wireless sensor networks have emerged considerable popularity due to their flexibility in solving problems. A priority-enhanced medium access control protocol, designed for critical traffic in Wireless Sensor Network (WSN). Exceeding the required delay bound for unpredictable and emergency traffic could lead to system instability, economic and material losses, system failure, and, ultimately, a threat to human safety. The priority MAC protocol does not guess to the Non critical and periodic traffic categories in WSN. As a result collision occurs. CSMA/CA technique along with duty cycling to overcome the problem is being proposed.