Objective: Little research has investigated children's physical activity levels during school recess and the contribution of recess to school day physical activity levels by weight status. The aims of this study were to examine non-overweight and overweight children's physical activity levels during school recess, and examine the contribution of recess to school day physical activity. Design: Cross-sectional. Setting: Four elementary schools located in Nebraska, United States of America (USA). Methods: Two hundred and seventeen children (99 boys, 118 girls; 47.9% overweight) wore a uni-axial accelerometer for five consecutive school days during autumn 2009. The proportion of time spent engaged in sedentary (SED), light (LPA), moderate (MPA) and vigorous (VPA) intensity physical activity during recess was determined using age-specific accelerometer thresholds. Results: Overweight children engaged in more %MPA and less %VPA than non-overweight children, respectively. No differences were found between overweight and healthy weight children's moderate-to-vigorous physical activity (MVPA). Recess contributed 16.9% and 16.3% towards non-overweight and overweight children's school day %MVPA, respectively. Conclusion: Examining %MVPA as an outcome variable may mask differences in recess physical activity levels between non-overweight and overweight children. Future research is needed to establish why healthy weight and overweight children engage in differing levels of %MPA and %VPA during recess.