We report on the generation of ultrashort light pulses from a Nd:YAG laser, passively mode locked by an intracavity frequency doubler in a nonlinear mirror arrangement. The pulse duration in the range of 20–25 ps is the shortest obtained so far from a Nd:YAG laser mode locked by this technique. In addition, the mode locking with frequency doubling crystal has provided in this experiment second‐harmonic radiation amounting up to 38% of the fundamental radiation output and single‐pass conversion efficiency of about 80%.