Diabetes is an important cause of morbidity and mortality in Africa. Although a dramatic increase in disease burden is projected, it remains to be seen what effect the ongoing devastation of HIV disease will have on the epidemiology of such chronic diseases as diabetes. Recent data on type 2 diabetes prevalence indicate low rates in some rural populations, moderate rates similar to those in developed areas in some countries, and alarmingly high rates in others. The frequent observation of moderate to high prevalence of impaired glucose tolerance, particularly in populations with a low prevalence of diabetes, may indicate the early stage of a diabetes epidemic. Risk factors include urbanization, age, and family history of disease, as well as such modifiable risk factors as adiposity and physical inactivity. For type 1 diabetes, limited data indicate that the prevalence is low in sub-Saharan Africa and that onset occurs later in life there than in other parts of the world. Mortality associated with diabetes is unacceptably high and is disproportionately due to preventable acute metabolic and infective causes. With long duration of disease, there is a high frequency of hypertension and microvascular complications. The apparent low frequency of chronic macrovascular complications needs fuller documentation - as does the apparent high frequency of hypertension even in the non-diabetic population. Efforts to prevent this disease and its complications in Africa are impeded by inadequate health care infrastructure, inadequate supply of medications, absence of educational programs, and lack of available health care facilities and providers.