A wireless system supporting concurrent physiological signal monitoring of multiple freely moving rats is presented. The wireless communication frees the subjects from the hassle of wires and reduces wire artifacts during recording. A combination of EEG and accelerometers eliminates the necessity for complicated video installation as well as time-consuming and tedious analysis of recorded videos. Supporting concurrent monitoring of multiple subjects saves the experiment time and the hardware/setup cost. A time division multiple access (TDMA) based medium access control (MAC) method, which incorporates a low-overhead clock synchronization approach as well as a packet retransmission method, was developed to coordinate the wireless data transmission. The system was installed on 3 freely moving rats for concurrent signal monitoring. The performance results show that the system supports more than 24-h continuous monitoring and very high data integrity (>99.98%) is achieved.