OBJECTIVES:Obesity prevalence is increasing worldwide and associated with a high health risk. Unfavourable psychological factors, lower self-ratings of health and worse health-related behaviour can be found in individuals with a low socioeconomic status (SES). Therefore, the aim of our study was to investigate whether normal weight vs. obese subjects with a high vs. low socioeconomic status (SES) differ with regard to self-perceived health, quality of life and health-related behaviour. METHODS:Data of the Austrian Health Interview Survey (ATHIS) 2006/07, precisely of 8015 subjects were analysed stratified by sex and adjusted by age concerning these outcomes. RESULTS:The results have shown that men and women with a low SES differ significantly from those with a high SES in terms of self-perceived health, quality of life, intensity of physical activities, alcohol consumption, and eating behaviour (men: p <0.001; women: p<0.001). A significant interaction between the body mass index (BMI) and SES occurred in men concerning quality of life in the domains physical (p<0.05) and psychological health (p<0.01), in women as to self-perceived health (p<0.01), quality of life in the domains physical health (p<0.01) and environment (p<0.05), as well as physical activities (p<0.01). CONCLUSION:The SES has a strong negative impact on health-related variables, especially in obese subjects, and therefore risk assessment in the primary health-care setting should include socioeconomic factors. Furthermore, a continued strong public health programme is required with an absolute priority placed on obese subjects of low SES.