Fusarium is a newly emerging fungal pathogen associated with significant morbidity and mortality in the immunocompromised host. We have reviewed our hospital's experience with Fusarium between 1985 and 1995. Fusarium species were isolated from 22 specimens, representing 11 patients. Cases were not clustered by time period. The median age of the patients was 36.5 years (range 17-69 years). The sources of the organism were 12 skin lesions from eight patients, seven blood cultures from two patients and one specimen each from a Hickman catheter tip, nail clippings and a bronchoalveolar lavage. Seven of the patients had chemotherapy-induced neutropenia when the Fusarium was isolated. Five of them developed invasive fusarosis during acute leukaemia induction treatment. They remained neutropenic, and none survived. The other two patients recovered from neutropenia and were treated successfully for this infection. The remaining four patients were not neutropenic or immunocompromised. Three grew Fusarium from skin or nail clippings and one from bronchial alveolar lavage (BAL). There was no evidence of invasive disease in any of the four. None of them received antifungal therapy, and they were all alive at last follow-up. We conclude that Fusarium is a newly emerging infection in neutropenic patients. A high index of suspicion, especially for skin lesions, will help in early diagnosis before systemic and visceral dissemination. Excision of the initial focus of infection and antifungal therapy, aided by speedy neutrophil recovery, are likely to protect patients threatened with these fatal infections. Fusarium isolated from non-neutropenic, non-immunosuppressed patients is not significant and does not merit systemic antifungal treatment.