BACKGROUND: Psychosocial stressors may mediate the effect of social status on the metabolic syndrome (MS). The paper explores this hypothesis in a random sample of the general population. DESIGN: A total of 3462 women and 2576 men aged 20-97 years from the Copenhagen City Heart Study. METHODS: An MS index was defined from the seven components: waist-hip ratio, high-density lipoprotein (HDL)-cholesterol, triglycerides, systolic blood pressure (SBP), blood glucose, C-reactive protein (CRP) and fibrinogen. Social status was measured by educational level. Psychosocial factors included fatigue and depression, perceived stress, social network and cohabitation. Behavioural factors were smoking, alcohol and physical activity. RESULTS: There was an inverse social gradient in the prevalence of the seven components of the MS. The age-adjusted odds ratio (OR) (95% confidence interval) for occupying the most disadvantaged quintile, comparing highest with lowest educational level, were for men and women, respectively: waist-hip ratio 0.48 (0.34-0.69) and 0.48 (0.33-0.69); HDL-cholesterol 0.61 (0.45-0.84) and 0.46 (0.33-0.64); triglycerides 0.71 (0.51-0.98) and 0.37 (0.25-0.53); SBP 0.64 (0.44-0.92) and 0.76 (0.50-1.15); blood glucose 0.57 (0.41-0.80) and 0.55 (0.38-0.78); CRP 0.53 (0.37-0.74) and 0.44 (0.31-0.63), and fibrinogen 0.50 (0.35-0.70) and 0.56 (0.38-0.82). The pooled OR for having an MS index score of 3 or more was 0.32 (0.24-0.42) for highest versus lowest educational level. A higher fatigue and depression score in both sexes and a lack of social support in men were associated with the MS, as were smoking, low alcohol consumption and a lack of physical activity. However, OR for educational level were not affected by adjustment for the psychosocial or behavioural factors. CONCLUSIONS: There is a strong inverse social gradient in the prevalence of the MS, which is not explained by psychosocial or major behavioural factors.