SummaryTerbinafine (Lamisil®) is a synthetic allylamine antifungal which has been shown to be fungicidal against dermatophytes and a number of yeasts and moulds. Topical application of terbinafine 1% cream has been shown to be a highly effective short‐duration therapy for dermatophytosis of the skin. The aim of this multicentre, double‐blind, parallel‐group study was to compare the safety and efficacy of terbinafine 1% cream, applied twice daily for 1 week, with clotrimazole (Canesten®) 1% cream, applied twice daily for 4 weeks, in the treatment of tinea pedis.One hundred and seven patients with mycologically proven tinea pedis received 1 week of terbinafine 1% cream, followed by 3 weeks of placebo, and 104 patients received clotrimazole 1% cream for 4 weeks. Mycological cure (negative microscopy and culture) and effective treatment (mycological cure with no or minimal signs and symptoms) were assessed 4 and 6 weeks after commencing therapy.Mycological cure rates were 93·5% for terbinafine and 73·1% for clotrimazole (p = 0·000l) at 4 weeks, and 97·2% for terbinafine and 83·7% for clotrimazole (P = 0·0001) at 6 weeks. Effective treatment rates at 4 weeks were 89·7% for terbinafine and 58·7% for clotrimazole (P = 0·0001), and 89·7% for terbinafine and 73·1% for clotrimazole (P = 0·002) at 6 weeks.The results show that 1 week of terbinafine b.d. is more effective than 4 weeks of clotrimazole b.d., in terms of both mycological cure and