Subcapsral prostatectomy was performed in a 75-year-old male, with the diagnosis of benign prostatic hyperplasia. Total prostate volume was 105 ml by transrectal ultrasonography (TRUS) and the excised prostate weighed in 90 g. After the surgery, he recovered from urinary disturbance once, but, he again complained of severe dysuria 12 days after the surgery. With the aim of non-invasive examination, we performed TRUS at voiding. Urethral stricture was definitely diagnosed using TRUS during micturition. Thus voiding TRUS was very effective in diagnosing urethral stricture.