The sample of this study comprised 9,991 adults who participated in the Azorean Physical Activity and Health Study, Portugal. Body mass index was calculated from self-reported weight and height and used as a depended variable. Physical activity was assessed by the International Physical Activity Questionnaire—short version, participants were classified in three categories according to their METs min/week values: low physical activity level, moderate physical activity level, and health-enhancing physical activity. Smoking status, alcohol consumption, and socio-economic status were also collected. Results showed that the prevalence of overweight and obesity was 33.5 and 18.8% in women, and 45.8 and 16% in men, respectively. The prevalence of health-enhancing physical activity individuals was 23.6% for women and 43.8% for men. Logistic regression analysis showed that age was a predictor of overweight and obesity, in both genders. Smoking status was negatively associated with overweight and obesity, in both genders. Men with low physical activity level and higher sitting time (≥3 h/day) were more likely to be obese. Low socio-economic status and alcohol consumption were found to be predictors for overweight and obesity for women. In summary, the prevalence of overweight and obesity among Azorean adults is high. Targeted programs aimed to lower the prevalence of overweight and obesity, among the Azoreans, should focus on elderly, on women with low socio-economic status, and on men aged 26–40 years, due to the higher prevalence of overweight and obesity and low levels of physical activity observed in these groups. Am. J. Hum. Biol., 2008. © 2007 Wiley-Liss, Inc.