OBJECTIVE: The aim of this work was to investigate the associations between homocysteine levels and several lifestyle-related factors, in a population-based sample of Greek adults. METHODS: During 2001-2002, we randomly enrolled 1128 men and 1154 women, from Athens area. The sampling was stratified by the age-gender distribution of the underlying population. Among several demographic, lifestyle, clinical and biochemical factors, we measured plasma total homocysteine levels. For the present analysis, we excluded people who had a history of cardiovascular disease. RESULTS: Homocysteine values were higher in men as compared to women (14.5+/-6 vs. 10.8+/-3.5 micromol/l, p<0.001). Twenty-five percent of men and 15% of women had plasma homocysteine levels >14 micromol/l. Postmenopausal women had higher homocysteine levels (12.0+/-5.2 vs. 9.9+/-2.9 micromol/l, p<0.001). The lifestyle factors most strongly associated with plasma total homocysteine were number of cigarettes smoked (r=0.12, p=0.004), fruits (r=-0.12, p=0.006) and vegetables consumption (r=-0.15, p=0.02), alcohol (r=0.11, p=0.04) and coffee drinking (r=0.10, p=0.03). Additionally, aerobic exercise was related with lower homocysteine levels as compared to anaerobic or sedentary life (11.0+/-2.6 vs. 12.4+/-2.5 vs. 12.5+/-2.3 micromol/l, respectively, p=0.04). Multivariate analysis after adjusting for several potential confounders confirmed the previous associations. No relationship was observed of homocysteine with the Mediterranean diet score (r=0.02, p=0.85). CONCLUSIONS: Several lifestyle-related factors were associated with homocysteine levels. Identifying and understanding modifiable factors related to homocysteine, a possible risk factor for vascular disease, might be especially important for the public health.