Background. Obesity is an important public health issue and its prevalence is reaching epidemic proportions in both developed and developing countries. The aim of the present study was to determine associations of overweight (OW), obesity (OB) and abdominal obesity (AO) with marital status and educational level in Greek adults of both genders based on data from the National Epidemiological Survey on the prevalence of obesity. Methods. The selection was conducted by stratified sampling through household family members of Greek children attending school during 2003. A total of 17,341 Greek men and women aged from 20 to 70 years participated in the survey and had anthropometric measurements (height, weight, and waist circumference) for the calculation of prevalence of OW, OB and AO. WHO cut-offs were used to define overweight and obesity categories. Waist circumference of more than 102 cm in men and 88 cm in women defined AO. Marital status and educational level were recorded using a specially designed questionnaire and were classified into 4 categories. Results. The overall prevalence of OB was 22.3% (25.8% in men, 18.4% in women), that of OW 35.2% (41.0% in men, 29.8% in women) and that of AO 26.4% in men and 35.9% in women. Ahigher risk of OB was found in married men (OR: 2.28; 95% CI: 1.85-2.81) and married women (OR: 2.31; 95% CI: 1.73-3.10) than in the respective unmarried ones. Also, a higher risk of AO was found in married men (OR: 3.40; 95% CI: 2.86-4.03) and in married women (OR: 2.40; 95% CI 2.00-2.88) compared to unmarried ones. The risk for being obese was lower among educated women (primary school, OR: 0.76; 95% CI: 0.60-0.96, high school, OR: 0.58; 95% CI: 0.46-0.74 and University, OR: 0.64; 95% CI: 0.49-0.81) than among illiterates. No significant differences were found among men. Conclusions. In Greek adults, marital status was significantly associated with obesity and abdominal obesity status in both genders while educational level was inversely associated with obesity status only in women.