Mode-locking of CW dye lasers are described. Three different methods: active mode-locking by acoustic loss modulation, pumping with mode-locked pulses and passive mode-locking by a saturable absorber, all resulted in stable continuous trains of tunable mode-locked pulses of various duration. Best results were obtained using passive mode-locking by a saturable absorber. The pulse lengths for this case were measured by auto-correlation technique to be as short as 1.5 ps. Factors influencing the mode-locking and possible improvements are discussed.