OBJECTIVE To compare the efficacy and safety of terbinafine 1% cream and clotrimazole 1% cream in the treatment of tinea pedis. METHODS Multicentre, double blind parallel group study. METHODS 32 general practices and one hospital. METHODS 256 patients with mycologically confirmed tinea pedis. Of the 211 patients evaluable, 107 were randomised to terbinafine (75 male, 32 female; mean (range) age 40 (12-81) years) and 104 to clotrimazole (79 male, 25 female; mean (range) age 36 (12-71) years). METHODS Terbinafine 1% cream applied twice daily for one week and inert cream applied twice daily for the next three weeks. Clotrimazole 1% cream applied twice daily for four weeks. METHODS Mycological cure (negative results on microscopy and culture) and effective treatment (mycological cure plus no or minimal signs and symptoms) measured at weeks 1, 2, 3, 4, and 6. RESULTS At week four rates of mycological cure were 93.5% for terbinafine and 73.1% for clotrimazole (p = 0.0001); and at week six 97.2% for terbinafine and 83.7% for clotrimazole (p = 0.001). Rates of effective treatment at week 4 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 week 6. CONCLUSIONS These results indicate that a one week course of terbinafine 1% cream is more effective in the treatment of tinea pedis than a four week course of clotrimazole 1% cream, both in terms of mycological cure and effective treatment.