Three cases of severe urethral strictures were treated by optic urethrotomy guided by transrectal sonography. With the aid of real time transrectal sonography, we were able to identify urinary bladder, prostatic urethra, stricture area and the tip of urethrotome. Ehile the tip of urethrotome and prostatic urethra were positioned in the same saggital plane, urethrotomy could be easily performed. This procedure is safe and time-saving and can be done even in the presence of urethral bleeding that usually make optic urethrotomy impossible to be undertaken.