Out-of-school time (OST) programs serve a large, diverse population of children, including those at increased obesity risk. In this study, parents' perspectives about nutrition and physical activity (PA) during OST were assessed. Design: Survey. Setting: Online. Participants: Six hundred parents with a school-aged child participating in programs from selected OST organizations. Main Outcome Measures: Parent perspectives about the importance and availability of different foods, beverages, and PA opportunities during OST, and OST program and parent involvement in promoting healthful environments. Analysis: Frequencies were used to describe parents' perspectives. Wilcoxon tests and logistic regression analyses were conducted to test for significant differences. Results: Most parents reported that it was important that their children have water (96.2%), fresh fruits and vegetables (79.0%), and PA (97.2%) during OST; fewer parents reported that these were regularly available. About two thirds of parents agreed that OST programs should promote healthy environments for children, whereas one third agreed that parents alone should be responsible for children's nutrition and PA. Conclusions and Implications: Results suggest that many parents would support efforts to improve OST nutrition and PA. Yet, there is a need to further understand the perceptions and motivations of different subgroups to enact successful obesity prevention efforts during OST. (author abstract)