摘要:Overweight and obesity is an emerging public health problem among school-aged children in Bac Giang city in the Northen part of Vietnam recently. This study aims to identify overweight-obesity prevalence of secondary school children in this city and it’s associated factors. The study was a nested case control in a cross-sectional study design in 1528 secondary students selected from 4 secondary schools in 2 inner communes and 2 suburban communes of Bac Giang city, Vietnam. Result: Overweight prevalence among secondary school students in Bac Giang was 6.7%, the prevalence of obesity was 2.0%. Overweight and obesity is more prevalence in male students, inner communes and students from family have higher income and higher food expense. Overweight and obesity was associated with higher energy intake, more fat consumption, having supplement meals and bedtimemeal, increased physical activities and increased sleep duration. Conclusion: Education campaign targeting reducing overweight and obesity should target both parents about dietary adequacy and balance and children about more physical activities.