Introduction: Obesity is the most prevalent form of nutritional disorder in many of the affluent countries. Obesity is a state of excess adipose tissue mass. Materials and Methods: Secondary data analysis of a school-based cross-sectional study in a rural and urban school of Kochi city. Weight, height, sex, and age routinely recorded by health visitors. Height, weight, and body mass index (BMI) standardized for age and sex. SD score >1.04 for BMI (>85th centile) was defined as overweight and >1.64 (>95th centile) as obese. Results: Out of the 254 girls of the rural school, 6 were obese (8.74%) and 25 were overweight (42.66%). Of these, obesity and overweight were more common among 12-year-old girls, 6.06% and 12.12%, respectively. Of the 220 girls of urban schools, 6 were obese (11.08%) and 21 were overweight (49.9%). Of these, obesity and overweight were more common in the 13 years old age group of 3 (5.56% and 8 (14.81%), respectively. Of the 191 boys of the rural school, only 1 (1.27%) was obese and 12 (29.13%) were overweight. Of these, obesity and overweight were more in the 14 year age group of 1 (1.27%) and 4 (5.06%), respectively. Of the 272 boys of the urban school, 15 (21.91%) were obese and 38 (55.74%) were overweight. Of this, obesity was more among the 14-year-old children. Obesity in girls showed no statistical significance with the urban and rural population (P = 0.9,64,233). Conclusions: Obesity is a serious health issue, resulting in both mortality and morbidity. We need to promote early intervention programs which should be aimed at weight reduction. Parents and children must be counseled not to eat junk foods and carbonated drinks.