Since the initial studies of Gentles1 demonstrated the clinical efficacy of griseofulvin in the treatment of experimental animal mycoses, there has been rapid application of this drug in the treatment of human dermatomycoses. In fact, its value in the management of many human superficial fungous infections has been too well documented to require further reiteration. As with any new medication, fuller evaluation must be held in abeyance until long-term studies have been completed with large numbers of patients. Among the many questions which remain unanswered, the possibility of delayed, undesirable side-reactions in persons receiving griseofulvin therapy, and the emergence of strains of griseofulvin-resistant fungi from subjects under treatment, certainly must be considered. Unpublished observations in our department2,3 have indicated that a number of patients with dermatomycoses being treated with griseofulvin, after showing an initial satisfactory clinical response, failed to evidence further improvement on continued treatment at the same