The aim of this study was to estimate the effect of plasma total cholesterol, HDL-cholesterol and triglycerides on risk of cerebrovascular disease. The Copenhagen City Heart Study is a prospective population study with 14.223 and 12.411 participants in first (1976-78) and second (1981-83) examination, respectively, where plasma lipids were measured along with other variables. Acute cerebrovascular cases were recorded during 12-year follow-up and the associations between lipid levels and risk of cerebrovascular disease were estimated using the Cox regression model. Significantly increased risk of ischaemic cerebrovascular disease was associated with: total cholesterol levels > 8 mmol/l, decreasing HDL-cholesterol, and increasing triglyceride levels. The association with HDL-cholesterol and triglycerides was log-linear and relative risks (95% confidence intervals) corresponding to increase by 1 mmol/l were: 0.53 (0.34-0.83) and 1.12 (1.07-1.16), respectively. The relative risk for total cholesterol < or = 8 mmol/l was constant (non log-linear association). These associations did not vary significantly between women and men.