The charts on 241 patients, consecutively undergoing a total of 2043 transurethral resections of bladder tumors and subsequent controls, were reviewed to find the incidence and possible causes of postoperative urethral stricture. The incidence of urethral stricture was 15% in males and 4% in females, but less than one-third were symptomatic. The strictures were found distally in the urethra in 83% of the patients and were treated with optical urethrotomy. Cumulated duration of postoperative catheterization was significantly longer and size of resectoscope used larger in patients with stricture. Repeated transurethral instrumentations may increase the risk of stricture development.