Ten patients with post-prostatectomy urinary incontinence underwent collagen implantation via the transrectal ultrasonographic guided method. Mean followup was 14 months (range 9 to 18 months). The procedure was performed through the perineum with the patient under local or epidural block anesthesia. The mean amount of collagen implantation was 20.0 ml. (range 10 to 37.5) and the mean number of treatments was 1.5 sessions (range 1 to 3). Results were successful in 6 patients, 1 of whom was completely cured (became dry). There were no marked complications associated with this procedure. We previously performed collagen implantation under cystoscopic observation. However, the ultrasonography guided method allows for the bladder neck to be identified and the needle to be positioned with real-time monitoring. After insertion of a urethral balloon catheter, the bladder neck and needle can be visualized clearly by transrectal ultrasonography. In our series the average amount of collagen injected was less than in the conventional method but the results were superior. In conclusion, transrectal ultrasonographically guided collagen implantation via the transperineal approach may be superior for the treatment of urinary incontinence.