The clinical efficacy of five ketoconazole (CAS 65277-42-1) topical formulations (three gels and two creams) was evaluated in 50 patients suffering from fungal infections in an open uncontrolled pilot study. Each formulation contained selected permeation enhancers providing high permeability in vitro. The patients were randomly divided into five groups each of ten persons. Each group was assigned to a selected topical formula which was applied to the diseased skin twice daily for four weeks or until complete clinical improvement. The clinical evaluation of treatment effects was based on the following criteria: size of lesion, erythema, scaling and severity of itching (four grades each). The patients were considered cured after the disappearance of these clinical symptoms and negative potassium hydroxide and Wood's light examination tests during the follow-up period. The results showed that the overall therapeutic response to the treatment was 96.7% and 93% for the hydroxypropylmethyl cellulose gel containing menthol and sodium carboxymethyl cellulose gel containing isopropyl myristate, respectively. Creams (w/o and o/w) achieved 90% and 87% improvement after 2.5 weeks, respectively. The lowest clinical response (86.5% improvement) with the longest duration of treatment (3 weeks) was observed with sodium carboxymethyl cellulose gel containing oleic acid.