BACKGROUND: Butenafine hydrochloride, a potent new benzylamine with fungicidal activity, has been extensively studied and approved for topical use in Japan. Results reported here are from one of the first major North American butenafine clinical trials. OBJECTIVE: We evaluated butenafine in the treatment of tinea pedis in a controlled, randomized, double-blind trial. METHODS: Of 80 patients with positive fungal cultures, 40 applied butenafine 1% cream and 40 applied vehicle to the affected area once daily for 4 weeks. Efficacy was assessed during treatment and 4 weeks after. RESULTS: Significantly more patients using butenafine than using vehicle had mycologic cure (butenafine, 88%; vehicle, 33%) and effective clinical response (butenafine, 78%; vehicle, 35%). Differences between treatment groups were greatest (p < 0.001) 4 weeks after treatment. CONCLUSION: Butenafine applied once daily for 4 weeks resulted in an effective clinical response and mycologic cure of tinea pedis during treatment. Patients continued to improve for at least 4 weeks after treatment.