Botulinum toxin type A (BTX-A) has been used to treat urethral and prostatic diseases (off-label uses). Injection of BTX-A into the external sphincter of patients with detrusor external sphincter dyssynergia has been shown to successfully lower postvoid residual volumes and detrusor pressures. Average efficacy is 3 to 4 months, but long-term effects on detrusor leak point pressures or renal function are unknown. Injection of BTX-A into the prostate has shown promising short-term results (≤ 12 months) in improving the symptoms, postvoid residual volumes, maximal urinary flow rates, and prostate sizes in patients with benign prostatic hyperplasia. The mechanisms of action and long-term durability of this treatment modality are unknown. Evidence supporting the use of BTX-A in treating detrusor hypocontractility, pelvic floor dysfunction, postpubovaginal sling retention, urethral stricture, prostatitis, and chronic pelvic pain syndrome in men is preliminary and deserves further evaluation.