Twenty-three patients were enrolled in a randomized, double-blind trial of terbinafine 1% cream compared with placebo vehicle in the treatment of tinea pedis. Of the 20 patients who were evaluated for efficacy, 10 received terbinafine and 10 received placebo. Except for the terbinafine-treated patients being an average of 1 lyears older than the patients receiving placebo and the median duration of disease being 6 weeks longer in the placebo group, the two groups were demographically and clinically similar. Results of mycologie tests and clinical findings showed terbinafine to be significantly more effective than placebo in the treatment of tinea pedis. Significantly more terbinafine-treated patients than placebo-treated patients showed conversion to negative culture and microscopy at end of therapy and a significant reduction in scored signs and symptoms. Overall efficacy at follow-up (combined mycologie and clinical findings) was also significantly greater in the terbinafine group (78%) than in the placebo group (zero) (p < 0.001). Unexplained elevation of liver function test results was noted in three placebo-treated patients and in one terbinafine-treated patient, but these changes were not considered clinically relevant or drug related. © 1990, American Academy of Dermatology, Inc.. All rights reserved.