Objective: Childhood obesity is a health problem that should be taken into account for the fact that it progresses as adult obesity; serious increases occur in morbidity and mortality due to complications; and most importantly, it can be generally prevented. In our study, we researched obesity frequency in child-ren at 6-11 years of age, and the factors that play a role in its development. Methods: 3963 children at 6-11 years of age from 32 of 71 elementary schools located in Yenimahalle district of Ankara along with their parents were selected to participate in the study. Age, height, weight, and gender of children and their parents; appetites of the children; their frequency of consuming fast food; their parents' level of education and income; and the time spent by the children on TV and computer were evaluated. BMI (body mass index) values of the participants were calculated and compared with their socio-demographic characteristics. Results: It was found that 11.1% (n=438) of the children were overweight, and 7.5% (n=299) of them were obese. Frequency of obesity was 15.7% (n=18) in the children whose mothers and fathers were both obese. It was found that frequency of obesity increased as BMI averages of children's mothers and fathers increased (p<0.001). 64.9% of the parents of the obese children were pleased with their children's weight. It was found that the frequency of being pleased with children's weight was 72.2% in cases where both mothers and fathers were obese. Two out of every three children had problems in meals, and 48.2% of the children did not have a habit of regularly having breakfast. 69.6% of all children had a habit of eating junk food between meals. The frequency of obesity was found to be high at a significant level in the children who spent more time on TV and computer (p<0.05). Conclusion: Result of this study shows that eating habits and sedentary life style play an important role in childhood obesity