Red light of a krypton laser (lambda = 647 nm) was used for treatment of patients suffering from herpes zoster (n = 4), postherpetic neuralgias (n = 8) and herpes simplex recidivans in loco (n = 13). The afflicted skin was irradiated daily for ten days (laserpower 50 mw, exposure time 90 sec). Improvement was observed in 7 out of the 12 patients suffering from herpes zoster and postherpetic neuralgias respectively, and in 8 out of 13 patients afflicted with recurrent herpes simplex.