In order to provide gigabit per second wireless communication, various standards have been proposed and implemented in recent years. Since the millimeter-wave (mm-wave) communication enables uncompressed high-speed data transfer with a minimum delay, it is considered to be the most promising technology to alleviate the pressure of the increasing demand of the spectrum resource. In this paper, a compact and highly efficient mm-wave transmitter is presented. The proposed injection-locked binary phase-shift keying (BPSK) transmitter can deliver a 10.2 dBm output with an efficiency over 10%. The proposed transmitter occupies 0.105 mm(2) chip area in 65 nm CMOS process.