OBJECTIVES:    According to WHO, obesity is a contemporary disease which threatens peoples’ health and health-related quality of life (HRQoL).  The prevalence of obesity in Greece, in both genders, is among the highest in Europe. Despite the cost of treating obesity, research in this area is generally under-funded. The aim of the study was to assess the physical and mental health of Greek obese people compared to the general (non-obese) population. METHODS: Data was obtained from a representative sample (N=981) of the general non-institutional population in Greece. The study was carried out in 2006 and participants were face-to-face interviewed. Participants with a BMI ≥30kgr/m2 (N=161) were compared to the rest of the sample in terms of physical and mental health as measured by the SF-12 questionnaire The confounding effect of demographic (gender, age, education) and disease-related variables (hypertension, hyperlipidaemia, diabetes and other cardiovascular problems) were controlled for using ANCOVA. RESULTS: Most obese participants were female (57.8%) and the mean age for the entire obese sub-sample was 54.8 (±15.5), compared to 45,8 (±18,4) for the non-obese participants. 40.4% of the obese participants suffered from at least one comorbid disease such as hypertension, diabetes, hyperlipidaemia, compared to a much lower 21.1% for the remaining sample. The unadjusted SF-12 scores for obese and non-obese participants were: PCS 44.9 (±12.0) and 50.5 (±9.8) (Mann-Whitney, P<0.001) and MCS 45.8 (±10.1) και 49.6 (±8.9) (Mann-Whitney, P<0.001). After adjusting for confounding variables, the respective scores were PCS 48.2 and 49.8 (P<0.05, R2=37.9%), and MCS 47.1 and 49.3 (P<0.01, R2=9.7%) respectively.   CONCLUSIONS: Obesity significantly affects physical and mental health. Recognizing the serious impact on health and HRQoL, and on the raising health care cost as well, formulating effective strategies to prevent obesity should become major public health priorities.