OBJECTIVES: To examine the prevalence of overweight and associated characteristics in a representative sample of children from schools in New York City (NYC). DESIGN: A cross-sectional survey with an in-person interview (including measurements of height and weight) and a household questionnaire. SUBJECTS: Second and ®fth grade students from schools in NYC participated. A total of 1 396, including 692 second and 704 ®fth grade, children were included in the analysis. MEASUREMENTS: Prevalence of overweight based on the body mass index (BMI) and the 85th or 95th percentile cutoff points from Cycles II and III of the National Health Examination Survey reference recently developed by the Centers for Disease Control and Prevention (CDC). The characteristics of overweight examined were: age, gender, socio-economic status, Hispanic origin, family structure, number of children in the household, meal preparation by children, food diversity and participation in the National School Lunch Program. RESULTS: Overweight based on the 85th percentile of BMI was 37.5% among second grade and 31.7% among ®fth grade children. Based on the 95th percentile, overweight was 19.9% and 17.8%, respectively. Overweight was associated with Hispanic origin, fewer children in the household, family structure and meal preparation by children. CONCLUSIONS: Overweight is prevalent among elementary school children in NYC. Studies in diverse geographically de®ned areas with diverse populations, are necessary to design effective prevention efforts. Primary prevention efforts in NYC should target Hispanics and take into consideration individual behaviour and family characteristics.