Most countries in oriental Asia have not yet experienced the 'western' coronary heart disease (CHD) epidemic despite substantial economic development. An exception has been Singapore. We compared mortality and CHD risk factors in Singapore with two Oriental locations, Hong Kong and mainland China, which have not experienced the CHD epidemic. Mortality data from World Health Statistics Annuals age standardised for each location and were supplemented by local data. Risk factor data was obtained from population-based surveys using similar protocols in each location. Measures included diet, blood lipids, blood pressure, height and weight. CHD mortality in the year chosen for comparison, 1994, was significantly higher for Singapore Chinese males [108 (95.2-119.1)] than Chinese males in Hong Kong [44.3 (40.2-48.2)] or China [45.5 (44.2-46.8)]. Female CHD mortality was also relatively higher in Singapore Chinese. The only CHD risk factor markedly higher in Singapore Chinese was serum cholesterol; Singapore males [5.65 (5.55-5.75)], females [5.60 (5.50-5.70)], Hong Kong males [5.21 (5.11-5.31)], females [5.20 (5.10-5.29)] and China males [4.54 (4.46-4.62)], females [4.49 (4.42-4.55)]. Dietary differences in saturated fat consumption were consistent with this. Although there was little difference in total fat intake, a higher consumption of dietary saturated fat and lower consumption of polyunsaturated fat, accompanied by higher serum cholesterol, appear to explain the relatively high CHD mortality in Singapore compared with Hong Kong and mainland China. Differences in body mass index, blood pressure and smoking between locations did not explain the differences in CHD mortality.