OBJECTIVES: To compare the effectiveness of behavioral treatment with that of antimuscarinic therapy in men without bladder outlet obstruction who continue to have overactive bladder (OAB) symptoms with alpha-blocker therapy. DESIGN: The Male Overactive Bladder Treatment in Veterans (MOTIVE) Trial was a two-site randomized, controlled, equivalence trial with 4-week alpha-blocker run-in. SETTING: Veterans Affairs Medical Center outpatient clinics. PARTICIPANTS: Volunteer sample of 143 men aged 42 to 88 who continued to have urgency and more than eight voids per day, with or without incontinence, after run-in. INTERVENTIONS: Participants were randomized to 8 weeks of behavioral treatment (pelvic floor muscle exercises, urge suppression techniques, delayed voiding) or drug therapy (individually titrated, extended-release oxybutynin, 5-30 mg/d). MEASUREMENTS: Seven-day bladder diaries and a validated urgency scale were used to calculate changes in 24-hour voiding frequency, nocturia, urgency, and incontinence. Secondary outcomes were global patient ratings and American Urological Association Symptom Index. RESULTS: Mean voids per day decreased from 11.3 to 9.1 (-18.8%) with behavioral treatment and 11.5 to 9.5 (-16.9%) with drug therapy. Equivalence analysis indicated that posttreatment means were equivalent (P < .01). After treatment, 85% of participants rated themselves as much better or better; more than 90% were completely or somewhat satisfied, with no between-group differences. The behavioral group showed greater reductions in nocturia (mean = -0.70 vs -0.32 episodes/night; P = .05). The drug group showed greater reductions in maximum urgency scores (mean = -0.44 vs -0.12; P = .02). Other between-group differences were nonsignificant. CONCLUSION: Behavioral and antimuscarinic therapy are effective when added to alpha-blocker therapy for OAB in men without outlet obstruction. Behavioral treatment is at least as effective as antimuscarinic therapy.