A prospective study of 726 cases of coroner's autopsies carried out over a period of two years (1st January, 1996 - 31st December, 1997) was reviewed. The causes and circumstances of death are defined and classified into natural and unnatural deaths. Fifty cases (6.3%) were children while the remaining 676 cases (93.1%) were adults in a male to female ratio of 2.6 to 1. The most common indications for coroner's autopsies were sudden unnatural deaths (SUDs) accounting for 485 cases (66.8%) and also sudden unexpected natural deaths (SUNDs) (241 cases) accounting for 33.2%. In the first category, road traffic accidents accounted for 86.7% of cases with deaths involving motor vehicle drivers and their passengers (41.8%); pedestrians (37.1%); and motorcyclists and their passengers (18.6%). The commonest causes of death in all road traffic accidents were craniocerebral injuries and haemorrhagic shock. In the second category the most common causes of sudden unexpected natural death were cardiovascular diseases resulting from complications of hypertension (54.7%) occurring in apparently healthy individuals. Other causes of death were pneumonia, pulmonary tuberculosis, typhoid fever and neoplastic diseases. This study showed that in Nigeria, with an increasing acquisition of dietary and life style habits of the developed western world, there is becoming a concomitant risk of deaths from road traffic accidents and sudden unexpected natural deaths from hypertensive cardiovascular disease.