The purpose of this study was to examine ecological correlates of obesity among Korean children. Cross-sectional data, including measurements of height and weight, were collected by questionnaire from 1,644 children in the fifth and sixth grades. A multiple logistic regression model incorporating individual- and school-level variables determined factors of childhood obesity. Intrapersonal factors associated with obesity included gender, computer use, and dissatisfaction with body image; significant interpersonal factors included low level of the father's education and encouragement to engage in physical activity. School-level factors that were significant predictors included location in Gyeonggi province, having two or more school exercise facilities, physical-education classes of 2 hr per week, higher fat content of school lunch, and higher number of classes in the school. The findings indicate that multifaceted, multilevel prevention strategies to manage and prevent childhood obesity should include behavioral modification, familial support, and improvement of school environments.