Yb:NaY(WO4)2 crystal is grown by the Czochralski method and a laser diode-pumped mode-locked Yb:NaY(WO4)2 femtosecond laser with a semiconductor saturable-absorber mirror (SESAM) is experimentally demonstrated. The average output power of 164 mW is obtained with the incident pump power of 8.6 W. The pulse duration is measured to be 246 fs with a repetition rate of 35 MHz at the central wavelength of 1035 nm.