BACKGROUND: Social status has been related with the prevalence and incidence of cardiovascular disease. The aim of this study is to investigate the relationships between socio-economic status (SES) and clinical and biochemical factors related to coronary heart disease, in a sample of cardiovascular disease-free men and women. DESIGN: Cross-sectional survey. METHODS: During 2001-2002, 1514 men (20-87 years old) and 1528 women (20-89 years old) from the Attica region (Greece) were randomly enrolled into the study. Trends in established and emerging cardiovascular risk factors were examined across the participants' socio-economic status. A special index was developed (years of school by annual income) and three socio-economic classes were created. RESULTS: An inverse relationship was found regarding all lipids and glucose levels across the tertiles of the SES index. An inverse association was observed between body mass index, waist-to-hip ratio and SES in men, but not in women. Furthermore, compared to the lowest tertile, individuals who were classified in the highest SES tertile had lower levels of C-reactive protein, fibrinogen, homocysteine, tumour necrosis factor-alpha, interleukin-6 levels and white blood cell counts, even after adjusting for various potential confounders. Finally, a considerable proportion of men and women reported lack of health knowledge and education. CONCLUSIONS: An inverse association between SES and factors related to cardiovascular risk exists, but the causal pathway itself requires more detailed explanation before the social status can have explanatory power.