Spurious signals are cancelled in a radio frequency (RF) transmitter. According to one method, a first baseband signal is fed into a first input port of an RF mixer of the RF transmitter, a carrier signal is fed into a second input port of the RF mixer, and an RF spurious signal is measured at an output port of the RF mixer. A baseband compensation signal is generated based on the first baseband signal and the RF spurious signal, and a modified baseband signal is generated by subtracting the baseband compensation signal from the first baseband signal. The modified baseband signal, instead of the first baseband signal, is fed into the first input port of the RF mixer.