STUDY OBJECTIVE--To determine trends in cardiovascular disease mortality. DESIGN--This was a descriptive study analysing mortality data. SETTING--Belgrade, Yugoslavia. PARTICIPANTS--The population of Belgrade in the age group 30-69 years was studied (about 760,000 inhabitants). MEASUREMENTS--Mortality rates were standardised directly using those of the "European population" as the standard, and regression analysis was undertaken. MAIN RESULTS--Between 1975 and 1989 "all causes" mortality increased by 27% (95% confidence interval 18.5, 35.9) in men and by 19% (11.6, 27.1) in women. The increase in cardiovascular disease mortality was 7% (1.7, 11.5) for men and 4% (0.2, 7.8) for women. Mortality from ischaemic heart disease fell in both sexes by 32% (23.0, 41.0), but mortality from other heart diseases rose by 31% (22.0, 40.2) in men and 25% (16.2, 33.0) in women. In men the death rate for cerebrovascular disease increased by 37% (27.8, 46.8), but in women the rate fell by 0.4% (-0.8, 1.6). Mortality from the observed causes of death was higher in men than in women. CONCLUSION--Cardiovascular mortality trends in Belgrade are similar to those in most eastern European countries. If the distribution of cigarette smoking and a "rich" diet in the Belgrade population is taken into account, a considerable decline in cardiovascular mortality trends cannot be expected in the near future.