OBJECTIVE Advances in endoscopic instrumentation and technique have expanded the urologist's armamentarium for effective and safe treatment of urethral strictures. This prospective study included 80 patients who presented with single, iatrogenic, annular strictures of the bulbar urethra. The length of the stricture was 1 to 2 cm, with an average of 1.5 cm. METHODS Patients were randomly divided into two groups: group A, 40 patients who underwent direct-optical endoscopic urethrotomy with a guide catheter via cold-knife incision at the 12 o'clock position (Sachse urethrotomy), and group B, 40 patients who underwent double direct-optical endoscopic urethrotomy with a guide catheter via cold-knife incisions at the 11 and 1 o'clock positions, followed by transurethral resection of all scar tissues (Guillemin's technique). The results obtained were analyzed and compared at 6 months, 12 months, 24 months, 3 years, and 5 years postoperatively by clinical evaluation, uroflowmetry, and retrograde and voiding urethrographies. RESULTS Group A obtained 95% good results at 6 months, 85% at 12 months, 55% at 24 months, 45% at 3 years, and 25% at 5 years. Group B obtained 98% good results at 6 months, 95% at 12 months, 90% at 24 months, 80% at 3 years, and 70% at 5 years. CONCLUSIONS The differences between the two groups are not significant at 6 and 12 months (P > 0.05). They are statistically significant after 24 months, 3 years, and 5 years (P < 0.05).