The treatment of urinary incontinence by endourethral Teflon injections applied to 43 male and female patients was studied. The advantage of the urethral pressure profile for diagnosing urinary incontinence is emphasized. With reference to sclerotherapy, suitable instrumentation for the endourethral and perineal injection of Teflon is described. Urinary incontinence as a frequent and socially severe complication following operations in the bladder neck area was cured by the injection of Teflon. The method used was safe, well tolerated, technically easy to handle, and was reapplied without any risk.