Abstract Objectives Removing chocolate milk from school cafeterias is an increasingly popular policy approach for reducing youth sugar-sweetened beverage consumption and improving health. Evidence on the impact of such policies in urban secondary schools, which is needed to inform future school-based health improvement efforts targeting our highest-need youth, is lacking. The objective of this study is to determine the impact of a school district's chocolate milk removal policy on racially/ethnically and socioeconomically diverse middle and high school students’ milk, calcium, and added sugar consumption. Methods Student-level lunch data were collected in the springs of 2016 (pre-chocolate milk removal policy) and 2018 (post-policy) during one lunch period each in 24 middle and high schools in a diverse urban school district. Linear mixed effects models adjusted for school-level demographic characteristics were used to assess changes in the proportion of students who purchased milk; the proportion of milk consumed; and the average grams of added sugar, ounces of milk, and grams of calcium consumed per student. Results Pre-policy, 3,158 students (mean 132 per school) participated in lunch data collection across all 24 schools; post-policy, 2,966 students (mean 124 per school) participated. There was a 13.6% (95% CI −16.4, −10.8) decrease in the proportion of students who purchased milk pre-policy (89.5%) to post-policy (75.9%). The proportion of milk consumed remained stable pre- (68.3%) and post-policy (66.3%; 95% CI for difference −4.1, 0.01). There was a statistically significant 3.8g decline in added sugar consumed post- policy (95% CI for change −3.9g, −3.6g) and no significant changes in ounces of milk or grams of calcium consumed. Conclusions Immediately post-chocolate milk removal from school cafeterias, fewer secondary students purchased milk. However, among students who purchased milk, consumption remained stable pre- and post-policy, and added sugar consumption significantly declined. Evidence on the longer-term impact of chocolate milk removal policies is necessary. Funding Sources This work was funded by the United States Department of Agriculture, National Institute of Food and Agriculture, (Grant ID: 2015-68001-23236); Technology and Design Innovation to Support 21st Century School Nutrition.