OBJECTIVE: In 2011, the National AfterSchool Association (NAA) adopted standards to guide delivery of physical activity (PA). We assessed after school sites' uptake of the five PA standards. METHOD: We conducted a descriptive study in fall 2013. NAA emailed 14,000 members requesting that afterschool site directors complete an online questionnaire regarding site characteristics, awareness and use of the standards, and implementation. We calculated implementation scores for each standard by summing points for their component best practices, and examined associations among site characteristics, implementation scores, and awareness and use of the standards. RESULTS: Among 595 respondents, 60% were aware of the PA standards and 43% used them for program planning. Awareness and use were significantly higher among NAA members and among sites that were accredited, licensed, or operated by a parent organization. PA content and quality scores were higher among those aware of and using the standards (p b 0.01) and correlated with scores for staff training and for program, social, and environmental support (p b 0.0001). CONCLUSION: We observed high recognition and use of the NAA PA standards in a national convenience sample of afterschool programs. Their uptake and use are promising lever for increasing the quality of PA in the afterschool setting.