1-[(4-Biphenylyl)-phenylmethyl]-1-H-imidazole (bifonazole, Bay h 4502, Mycospor) is a broad spectrum antifungal agent for the topical treatment of dermatomycoses. In addition to tolerability studies, a report is given on the results of 43 clinical studies of efficacy and tolerability involving 1129 patients in various countries. These were placebo-controlled double-blind studies, randomised comparative studies with reference preparations and open studies. They were carried out with bifonazole cream 1%, solution 1%, gel 1% and powder 1%. 58.6% of the patients tested suffered from dermatophytoses, 21.9% cutaneous candidoses, 14.3% from pityriasis versicolor and 5% from other skin infections. The therapeutic efficacy of bifonazole, assessed according to mycological and clinical findings proved good for the indications studied and administered once daily for a treatment period of 2 or 3 weeks. Tolerability - local and systemic - was good. There was no evidence of substance-related side effects.