In the article titled “Effectiveness of Peer-Based Healthy Living Lesson Plans on Anthropometric Measures and Physical Activity in Elementary School Students: A Cluster Randomized Trial,” published online February 10, 2014, and also in the April 2014 print issue of JAMA Pediatrics (2014;168[4]:330-337. doi:10.1001/jamapediatrics.2013.3688), several minor errors existed in the statistical methods used in the study. Once recalculated, the treatment effects were modified slightly; however, these modifications did not influence the original statistically significant differences between the treatment and control arms of the trial, and the results and conclusions remain unchanged. In addition, the third author’s last name should have appeared as “Rabbani” in the byline, Author Affiliations, and Author Contributions. This article was corrected online.