The activity of topically applied bifonazole was evaluated in vivo in the three androgen-dependent structures of the hamster flank organ, i.e. the pigmented spot, sebaceous glands and hairs. Topical bifonazole in our experience did not demonstrate any morphological effect on sebaceous gland and hair even when applied in the dosage of 3 mg/cm2/day. On the basis of our morphometric results we can conclude that topically applied bifonazole does not interfere with cutaneous androgen metabolic transformations in the pilosebaceous unit of the flank organ.