The present investigation is an appraisal of fluconazole in the treatment of onychomycosis caused by dermatophytes. The response to fluconazole of onychomycosis caused byTrickopkyton rubrumwas evaluated in the 46 most severely affected nails of 20 patients. The mean duration of fluconazole therapy was 9.3 months and the dose was 150 mg once a week. All fingernails and 92% of toenails were clinically and mycologically free of infection at the end of treatment. After 6 months follow-up the cure rate in toenails was 83% and in fingernails still 100%. No significant abnormalities were noted in laboratory test results. This study suggests that fluconazole is effective in the long-term therapy of onychornycosis.