The clinical charts of cancer patients with documented fungal infections hospitalized at G. Gaslini Children's Hospital, Italy, from 1980 to 1990 were reviewed. Thirty-seven episodes developing in 37 patients were identified, based on microbiological and/or histological documentation. Patients' age ranged from 3 months to 18 years (median 7 years). Twenty patients were treated for hematological malignancy and 17 had solid tumor. Seven patients (3 with leukemia and 4 with solid tumours), developed mycosis after bone marrow transplantation procedure. A history of neutropenia in the month preceding the documentation of fungal infection was present in 76% of cases (28 of 37). However, only 16 of 28 (55%) of these patients were still neutropenic at time of diagnosis. In 40% of the cases the fungal infection developed as primary infection not preceded by any febrile and/or infectious episode. Fungemias without evident organ localization accounted for the 40% of episodes with a mortality rate of 20%. The other 22 cases (60%) were classified as invasive mycoses; 9 of these patients died (41%). Mortality was higher among patients with mold infection (5 of 7, 72%), than in those with yeast infection (7 of 29.24%). Molds infections and invasive mycoses were virtually absent in the first part of our period of observation (1980-84), but emerged in the second period (1985-90) when also the incidence rate of fungal disease increased (from 2.67/10,000 person/day to 5.93), probably in relation with extensive construction works and with the implementation of a bone marrow transplantation program.