PURPOSE: Bladder outlet obstruction(BOO) in women is an uncommon condition with an incidence range of 2.7~29%. It is difficult to predict because there is a result of the lack of standard diagnostic definition for the evaluation and no typical diagnostic symptoms. We analyzed the clinical manifestation, urodynamic findings, and response to treatment in female BOO. MATERIALS AND METHODS: 140 women with non-neuropathic voiding dysfunction were evaluated. In all, 27 women had bladder outlet obstruction as indicated by our diagnostic criteria: non-neuropathic voiding dysfunction, maximal flow rate(Q(max)) or =30 cmH2O. Using 16 Fr urethral metal soundation for urethral evaluation, we classified the patients into two groups, the anatomical BOO group in case of resistance to soundation or the functional BOO group, for cases without resistance. We managed these patients with urethral dilation of up to 28 Fr in combination with the administration of alpha 1-blocker. RESULTS: The etiology of BOO was anatomical(37%, n=10), and functional(63%, n=17). In patients with anatomical and functional BOO, urodynamic parameters were similar in each group. In women with BOO, the management with alpha 1-blocker and/or urethral dilation significantly reduced International Prostate Symptom Score(IPSS) and residual urine volume. CONCLUSION: In patients with P(det)Q(max)>or=30 cmH2O, Q(max)