In a retrospective analysis, 79 allogeneic bone marrow recipients treated with AmBisome prophylactically or because of proven or suspected invasive fungal infection (IFI) were evaluated in 92 episodes. The median duration of treatment was 14 (range 1-112) days. The mean maximum dose given was 1.64 +/- 0.8 mg kg-1 day-1 and the mean total dose was 1.29 +/- 2.28 g. The overall incidence of reported adverse events was 194, of which none had a serious outcome. In six cases, the drug was withdrawn as a result of toxic or allergic reactions: dyspnoea and flush (3), urticaria (1), cholecystitis (1) and disorientation (one case, probably not related to AmBisome). No anaphylactoid reactions were seen. Laboratory findings, including low serum potassium (48% of the episodes), increased serum creatinine (38%) and increased serum sodium levels (7%), caused no major clinical problems. Thirteen cases of verified IFI were evaluated regarding the efficacy of AmBisome. Survival or cure of the mycotic infection occurred in 5/13 patients (38%). Two patients were treated with AmBisome (3.6 and 3.3 mg kg-1 day-1) because of verified IFI before BMT. One died of IFI. The other died of venoocclusive disease of the liver (VOD) without histological evidence of active IFI. We found a significant (P < 0.05) reduction in autopsy-proven IFI, 12/199 (6%) compared to the period when only conventional doses of amphotericin B were used, 26/227 (11%).