In this work, Sensor Multi Channel (SMC) Medium Access Control (MAC) has been proposed for wireless sensor networks. The SMC MAC uses a dedicated control channel and multiple data channels. The effective solution for the multi channel hidden terminal problem and missing receiver problem has been proposed in this work. The performance of the SMC MAC has been compared with that of the single channel CSMA/CA MAC by taking the throughput and latency as performance metrics. It has been shown that the multi channel MAC gives high throughput and less latency in high traffic conditions.