A clinical trial with retinoic acid (Airol) cream 0.05% applied topically was carried out on 50 patients suffering from tinea versicolor allocated to a random procedure. The results, judged in terms of cure rate, incidence of relapse and tolerance were very satisfactory. As regards the above mentioned criteria for a successful treatment, there was no significant difference between the lotion and cream groups. Repigmentation of the affected skin after retinoic acid occurred in a relatively shorter period compared with other anti-fungal preparations, especially when simultaneously exposed to sunlight. The therapeutic action on dermatophytes was discussed. It was pointed out that patients suffering from tinea versicolor are predisposed to dermatophyte infections and that cleanliness of the skin is a simple but essential way of preventing contamination with Malassezia furfur.