Urinary incontinence is one of the most common complications occurring after radical prostatectomy. We evaluated the efficacy of clenbuterol, a selective beta 2-adrenoceptor agonist, in the treatment of incontinence occurring after radical prostatectomy, using urodynamic assessment. Fourteen men (mean age, 68 years) with post-radical-prostatectomy incontinence were treated with 20 mg of clenbuterol twice a day for 1 month. The urodynamic assessment was performed on all patients before and after the administration of clenbuterol. A pad scoring system was used to gauge the severity of incontinence before and after treatment. At 1 month after administration of clenbuterol, 9 of the 14 patients (64%) had dramatic improvement in pad scores. Treatment failed in 5 patients (36%) with severe incontinence. The results of urodynamic studies showed that the mean functional urethral length of the patients with post-radical-prostatectomy incontinence increased significantly after treatment. These results suggest that clenbuterol can be used as an effective agent for treating mild-to-moderate stress incontinence after radical prostatectomy.