The aim was to evaluate the dietary habits and some lifestyle characteristics of Greek adolescents 12-17 years of age in relation to the prevalence of overweight/obesity.During 2004-2005, 2008 school-aged adolescents (1021 male and 987 female) were selected from all public schools located in the Vyronas region of Athens. The participation rate was 95%. Height and weight were measured and the body mass index (BMI) was calculated. Cut-off points for BMI defining obesity and overweight for gender and age were calculated in accordance with international standards. A semi-quantitative Food Frequency Questionnaire was applied and multiple logistic regression was used to investigate the association between dietary habits/lifestyle characteristics and overweight/obesity in adolescents.Eating cereals for breakfast and the number of meals per day (including snacks) were inversely associated with BMI in males. Furthermore, eating poultry as a meal and sedentary activities were positively associated with BMI in females, while eating breakfast more than five times per week and eating cereals for breakfast were inversely associated with BMI in females. Overall, 4.4% of males and 1.7% of females were obese and 19.2% of males and 13.2% of females were overweight.The consumption of cereals for breakfast and the daily frequency of meals consumed were associated with overweight/obesity in males, whereas the frequency of eating breakfast, the consumption of cereals for breakfast, the consumption of poultry, and the hours spent for activities excluding sports were associated with overweight/obesity in females.