Aim: The aim of the present study was to explore the prevalence of obesity in primary and secondary education students of Attica prefecture. Method and material: the sample studied consisted of 334 students of Primary and Secondary Education. Data were collected by the use of an anonymous questionnaire which included their demographic data and their personal and dietary habits. Obesity and overweight was calculated based on the internationally accepted standards of Body Mass Index (BMI in kg/m2). Analysis of data was performed using the SPSS 15 statistical package. Results: 81,7% of students questioned had a normal body weight, 17,1% were overweight and 1,2% were obese. The analysis of the results showed that students of Intermediate School were overweight compared to those of Elementary and High School with statistically significant difference, p=0,006. Boys were overweight compared to girls with statistically significant difference, p<0,001. Those watching television or playing electronic games more than 3 hours/day were overweight compared to those devoting 1-2 hours with statistically significant difference, p=0,043 Boys reported that had athletics more often compared to girls with statistically significant difference, p<0,001. The more increased the age the less had athletics, p<0,001. Students of Elementary School consumed more often food prepared at home and more juices, whereas less often sweets and soft drink compared to those of Intermediate and High School with statistically significant difference, p=0,008, p=0,003, p<0,001 and p=0,022, respectively. Girls preferred to consume sweets as well as light” products more often compared to boys with statistically significant difference, p=0,013, p=0,001, respectively. Conclusions: It is concluded that the main contributing factors for children and adolescent obesity is sex, age, increased amount of time spending in sedentary activities. It is deemed necessary to continuously inform the students and their parents regarding the role of balanced nutrition and physical exercise to the weight management.