A new CMOS XOR circuit based on pass transistors is proposed. It uses only six transistors to produce both an XOR and the complementary XNOR function. The circuit has full voltage-swing and negligible static power dissipation. A drawback is that the transistors need to be ratioed due to a feedback structure. Simulation results for the new circuit compared to simulation results for a reference XOR circuit indicated that the energy consumption was similar for the circuits. However, the propagation delay was 50% longer for the new circuit, due to the feedback structure. The main advantage of the new circuit was the reduction in device count from eight to six transistors.