In turning, the self-excited vibration, also called chatter, is undesirable as it gives rise to production problems. In this paper, in order to suppress chatter in the turning, the turning process is modeled as a two degree-of-freedom uncertain system with both hysteresis and delay, where a piezoactuator is introduced for the regulation of the cutting tool displacement. A robust adaptive control law is therefore proposed and the simulation results show that the proposed robust adaptive control law significantly eliminates the chatter phenomena.