Objective: We compared β 2 -adrenergic agonist therapy with clenbuterol (DT) and physiological therapy (PT) in a randomized study to establish the first line therapy for stress incontinence (SI). Method: The clinical efficacy of DT (group A), PT (group B), and a combination of DT and PT (group C) was investigated in 61 patients with SI by means of a 12-week randomized controlled study. The frequency and volume of SI and the patients' own impressions were used as the basis for the assessment of efficacy. Results: The SI improvement rates in groups A, B, and C were 76.9, 52.6, and 89.5%, respectively (P=0.0361). A significant therapeutic effect on the frequency of SI was observed in group B and group C at 2 weeks after the start of treatment (both P<0.05), and in all groups at 6 weeks (all P<0.01). The efficacy rates based on the patients' own impressions in groups A, B, and C were 84.6, 31.6, and 68.4%, respectively (P=0.0064). Conclusion: The β 2 -adrenergic agonist appeared to be clinically useful as a drug of choice for SI.