This prospective study was designed to describe problems that arise when Aboriginal people undergo anaesthesia, in order to develop guidelines for anaesthetists who are not accustomed to treating Aboriginal people. Data were collected on 1122 consecutive different individuals undergoing anaesthesia at Royal Darwin Hospital, 24.5% of whom described themselves as Aboriginal. Aboriginal patients were in a poorer physiological state than were non-Aboriginal patients. The prevalence of diabetes mellitus, renal disease and rheumatic heart disease reported in Aboriginal patients was very high. Communication difficulties were more commonly reported in Aboriginal patients; the most common difficulty was apparent shyness or fear, rather than actual language difficulty. The results suggest that the treatment of Aboriginal people involves diagnosis and management of diverse preoperative medical problems, and that better management may be achieved by learning simple cultural strategies and by adding Aboriginal interpreters and health workers to the anaesthetic team.