In a cross-sectional analytic study, we examined the differences in coronary heart disease (CHD) risk factors, including coagulation factors and platelet aggregation, among males from southern European countries and those of Anglo-Celtic descent who had widely different CHD standardized mortality ratios. The participants included 169 men aged 40 to 49 years, 27% of whom were born in southern European countries. The subjects had no history of heart disease and no other clinical conditions, or were not taking medications known to affect hemostasis. Data obtained included their medical history and CHD-related risk behaviors, blood pressure, height, weight, abdominal and pelvic circumference, and coagulation, fibrinolysis, platelet activity, lipids, and lipoproteins profiles. There were significant differences between the two groups in the prevalence of a positive family history, mean apolipoprotein A1 levels, and platelet aggregation responses to ADP. Other established risk factors, including coagulation factor levels, were not significantly different.