In a cross-sectional random survey of the whole of Singapore (2143 subjects aged 18-69 years), cardiovascular risk factors were measured by standardized techniques. For the analysis in the 18-69 year age group there was adjustment for ethnic group, age, body mass index, alcohol consumption and physical activity. Among serum lipids, high density lipoprotein (HDL-) cholesterol and fasting triglyceride were inversely related with partial correlation coefficients (r) of males -0.34 (P < 0.001) and females -0.26 (P < 0.001). There were no relationships between blood pressure and serum lipids except for direct ones with fasting triglyceride, being males (systolic r = 0.06, P = 0.066 and diastolic r = 0.12, P < 0.001) and females (systolic r = 0.11, P < 0.001 and diastolic r = 0.13, P < 0.001). Cigarette smoking, in males, was related to systolic blood pressure (inversely), with, compared to non-smokers, a reduction of 1.3 mm Hg (1.1%) in light smokers, 3.8 mm Hg (3.1%) in moderate smokers and 4.6 mm Hg (3.7%) in heavy smokers; there was no clear relation with diastolic blood pressure. Cigarette smoking, in males, was related to HDL-cholesterol (inversely), even after further adjustment for fasting triglyceride, with compared to non-smokers reductions of 0.03 mmol/l (3.4%) in light smokers, 0.09 mmol/l (10.3%) in moderate smokers and 0.12 mmol/l (13.8%) in heavy smokers. Cigarette smoking was related to fasting triglyceride (directly) but this was removed by further adjustment for HDL-cholesterol. Cigarette smoking was not related to low density lipoprotein cholesterol. These results are compared to those of other surveys.