Forty cases of gonococcal urethritis were treated with oxytetracycline using various dosage schedules; there were 37 cures and three failures. The most convenient and most effective dosage was found to be 250 mg. oxytetracycline, given as a single intramuscular injection of 5 c.c.A series of 40 patients with non-gono-coccal urethritis was also collected. Two cases of urethritis due to Trichomonas vaginalis and two due to Candida albicans were removed from the series. Of the 36 cases which remained, cure was obtained with the use of oxytetracycline in different dosages in 30 cases; six cases were failures. The dosage which gave the best result in the therapy of non-gonococcal urethritis was 250 mg. oxytetracycline (5 c.c.), given as a single intramuscular injection, plus 250 mg. orally, four times a day for four days.The effectiveness of oxytetracycline in the treatment of urethritis has not decreased.