Objectives: To examine the psychometric properties of the Neighborhood Environment Walkability Scale-Youth (NEWS-Y) and explore its associations with context-specific and overall physical activity (PA) among youth. Methods: In 2005, parents of children ages 5-11 (n = 116), parents of adolescents ages 12-18 (n = 171), and adolescents ages 12-18 (n = 171) from Boston, Cincinnati, and San Diego, completed NEWS-Y surveys regarding perceived land use mix-diversity, recreation facility availability, pedestrian/automobile traffic safety, crime safety, aesthetics, walking/cycling facilities, street connectivity, land use mix-access, and residential density. A standardized neighborhood environment score was derived. Self-reported activity in the street and in parks, and walking to parks, shops, school, and overall physical activity were assessed. Results: The NEWS-Y subscales had acceptable test-retest reliability (ICC range .56-.87). Being active in a park, walking to a park, walking to shops, and walking to school were related to multiple environmental attributes in all three participant groups. Total neighborhood environment, recreation facilities, walking and cycling facilities, and land use mix-access had the most consistent relationships with specific types of activity. Conclusions: The NEWS-Y has acceptable reliability and subscales were significantly correlated with specific types of youth PA. The NEWS-Y can be used to examine neighborhood environment correlates of youth PA. © 2009 Elsevier Inc. All rights reserved.