A clinical study was conducted to test the efficacy of fluconazole in the treatment of tropical deep mycoses. Two out of four patients with zygomycosis due to Conidiobolus coronatus who were treated with the drug were completely cured; the other two patients exhibited considerable improvement but could not be followed up. Two patients with eumycetoma, one due to an Acremonium sp. and one due to Pseudallescheria boydii, were treated successfully, whereas another patient with a eumycetoma caused by an unidentified fungus could not be followed up. A complete cure was achieved with one patient with African histoplasmosis and one with candiduria. A case of cerebral phaeohyphomycosis due to Cladosporium sp. showed some improvement but the patient later developed meningitis and died.