Objective: The aim of this project is to find out the prevalence of overweight and obesity in the high school children in selected schools of Mangalore and Manipal and also to study the association of obesity with different factors like Age, Sex, Physical activity etc. Methods: Cross sectional Study which included 500 participants from 10 selected schools in Udupi and D.K districts. 50 students were rd included from each school on the basis of 1 in 5 choosing every 3rd student. In schools with lesser attendance all were included. Following which they were explained the details about the study. Then their height and weight were recorded using standard measurements and the data was collected using the questionnaire. Results: The overall prevalence of obesity and overweight was found to be 2.6% and 3.0% respectively. Prevalence was found to be higher in males, those studying in private schools, staying in nuclear family, consuming fried foods-aerated drinks regularly and in those who do not exercise regularly. Conclusions: Childhood obesity is a major public health problem globally because of changes in lifestyle.