This study proposes a discrete-time integral terminal sliding mode controller (DITSMC) integrated with a sensorless maximum power point tracking (MPPT) method for a permanent magnet synchronous generator (PMSG)-based wind energy conversion system (WECS). The effects of the parameters of the proposed DITSMC on the convergence-time and the error-bound are investigated by the simulation studies. The dynamic performance of the DITSMC has been evaluated experimentally on a test bench for step-type wind changes. The optimum coefficient between the output voltage of the generator and the extracted power from the WECS is determined only for a wind speed by offline studies. Then, the MPPT can be provided using this coefficient for all wind speeds in the operating range of the WECS without any mechanical sensor. Additionally, the experimental studies show that DITSMC has better performance than the PI controller in terms of the settling time and thus the efficiency of the WECS.