Social status has frequently been found to be associated with the prevalence of coronary heart disease. Currently, in developed countries, it seems that the least advantaged social groups are at the greatest risk. This article addresses this issue in the Scottish population, using a cross-sectional sample of 10,359 men and women. Four measures of social status are used: level of education, years of education, housing tenure, and the Office of Population Censuses and Surveys' definition of social class based on occupation. By each of these four criteria, and for both sexes, the least advantaged have a significantly higher coronary heart disease prevalence (P less than 0.01). The odds ratios for housing tenure are highest, being 1.63 and 1.55 for men and women, respectively, comparing those who live in rented accommodation with owner-occupiers. After adjustment for a number of coronary heart disease risk factors, which are possible confounding variables, most, if not all, of the significant effect of education and occupation on coronary heart disease is removed. Housing tenure is still highly significant (P less than 0.001), with odds ratios of 1.48 and 1.45 for men and women, respectively. Smoking and fibrinogen are the most important confounding variables for men, and body mass index, high-density lipoprotein cholesterol, and triglyceride levels, the most important for women. When relationships among the social factors themselves are investigated, housing tenure is found to remove the significant effects of education and occupation in men, and of education in women. No other social factor removes the significant effect of housing tenure (P less than 0.001). Housing tenure in Scotland is thus found to be the most discriminatory measure of social status in relation to coronary heart disease.