No comparative clinical information on the properties of lipid-associated amphotericin preparations is presently available. In this single-centre retrospective analysis over a 5-year period the indications, efficacy and toxicity of true liposomal amphotericin (AmBisome) were compared with a lipid complexed preparation (Abelcet). In a novel approach APACHE III scores were used in addition to neutrophil counts, disease status and additional immunosuppression to accurately assess the severity of illness in both groups and enable valid comparison. Overall, AmBisome at a median dose of 1.9 mg/kg/d was found to have similar clinical outcome to Abelcet at a median dose of 4.8 mg/kg/d. Nephrotoxicity and electrolyte abnormalities were similar in both groups. Rigors and febrile episodes were more common with Abelcet. Prospective randomized comparative trials are required to clarify the optimum dosages and therapeutic and economic issues associated with these agents.