The late complications associated with two different irradiation schedules with multiple fractions per day (MFD) used for the treatment of prostatic carcinoma are analyzed in 91 patients. There is a relatively high rate of side-effects with fifteen patients (16.5%) developing severe complications due to the radiotherapy. Complications are generally localized in the urinary system and consist mainly of chronic cystitis and incontinence, with only a few exclusive gastro-intestinal problems. The causative factor seems to be pronounced fibrosis of the normal pelvic tissues.