Nine cases of skin and nail infection due to Fusarium oxysporum, diagnosed in Tuscany in the period 1985-97, are described. Two manifested as interdigital intertrigo of the feet and seven as onychomycosis. All were diagnosed on the basis of repeated mycological examination, direct microscope observation and culture, as well as histological examination of biopsy specimens in two cases of intertrigo. Fragments of the fungal colonies were examined by scanning electron microscopy (SEM) for more detailed observation of fungal morphology. All patients had normal immune status and a history of the infection extending several years. Four of the patients with onychomycosis were treated with oral itraconazole, and clinical and mycological recovery was achieved in three cases. Two others were treated with cyclopyrox nail lacquer, successfully in one case. One patient with intertrigo was treated with oral itraconazole and one with oral terbinafine; both were also treated and with topical drugs, however clinical recovery was not confirmed by the mycological results.