We report on the laser‐induced permanent changes of the critical current (Ic) and normal resistance (Rn) of YBa2Cu3O7−x(YBCO) step‐edge Josephson junctions. The 2‐ to 20‐&mgr;m‐wide junctions were prepared from a 200‐nm‐thick YBCO film deposited by a pulsed KrF excimer laser onto 300‐nm‐high steps etched in the LaAlO3substrate. The laser modification experiments were performed by illuminating the junctions at 50 K with a focused Ar‐ion laser beam of various intensities. Depending on the illumination power density, either increase or decrease of the junctionIchas been observed. In particular, after illumination at the 0.6×105W/cm2power level, a 75% enhancement ofIcand increase of theIcRnproduct up to 25% were obtained without a measurable change in the junction critical temperature. The laser‐induced modifications were very reproducible and remained unchanged even after a subsequent room‐temperature/helium thermal cycling of the sample. Photoassisted, thermally activated oxygen redistribution in the YBCO grain boundary region is proposed to explain the observed behavior. ©1995 American Institute of Physics.