Diabetes mellitus and its complications account for a high proportion of avoidable morbidity and premature mortality in people of South Asian origin living in the UK. This review examines available evidence as to why this might be and what can be done to address the problems. The sources for data were a Medline search by MeSH terms, free text and key authors by name, and relevant references, searched by hand, from all review articles in the AIM journals, up to April 1996. Most trials identified were epidemiological surveys. The high instance of diabetes and some of its complications do not have a single explanation. The early incidence of diabetes and its link with coronary heart disease may be partially explained by the central adiposity-insulin resistance syndrome. Predisposition to this is probably largely genetic but exacerbated by other factors such as diet, immune-inflammatory changes, and physical activity levels. There is less evidence to support conventional dietary risk factors and some for potentially deleterious effects of traditional Western dietary advice in this population. The impact of the genetic and environmental influences is exacerbated by suboptimal use of health services. The contribution of economic deprivation to the poor outcome of diabetes in these patients may be substantial. There is a considerable impact of psychosocial stress on morbidity, supporting the view that a narrow biomedical model will neither fully explain the problem nor provide solutions. To be successful, strategies for the secondary prevention of diabetes complications in British South Asians need to incorporate a number of paradigms: genetic, physiological, psychological, anthropological, and sociological. Recommendations for a multidimensional approach to this important clinical issue are proposed.