In the past several years society has witnessed a multi-disciplinary effort to end childhood obesity in the U.S. Investigators and practitioners have addressed both the input and output sides of the caloric equation. However, reducing caloric intake may deprive children of important nutrients for growth and/or energy. Scientific consensus now points to children's physical activity (PA), which, given adequate opportunity, is inherently modifiable. It is further documented that children establish lifetime patterns of PA during the elementary school years. Therefore, current information is needed about how public elementary schools in the U.S. have responded to the aforementioned national concern. Purpose--The purpose of this study was to examine PA opportunities (PAO) during the school day (minutes of PE and recess) for children in grades 1-6 in U.S. public elementary schools. Methods--Survey data on children's PAO (N=1050 U.S. schools; survey return rate=91%) provided by the National Center for Educational Statistics were analyzed using within-grade, between-group comparisons. Analysis/Results--One-way ANOVA's were calculated for each grade level's reported PAO by enrollment size, geographic region, school locale (rural, city, etc.), pupil socioeconomic status, and percent of minority pupils. The Scheffe procedure was used to make post hoc comparisons. Six principal findings emerged: a) PAO decreased from 222 to 204 min./week from grades 1 to 5 for the entire sample; however, minutes of PE increased from 85 to 98 min./week from grades 1 to 6; b) schools with smaller enrollments (<300) provided more PAO than schools in all larger categories (p<. 01); c) schools in rural areas provided more PAO than schools in towns, suburbs, and cities (p<. 01); d) schools in Western U.S. provided more PAO than schools in Southeast, Northeast, or Central U.S. (p<. 01); e) schools with a low minority enrollment (<6%) provided more PAO than schools with very high minority enrollment (>50%) (p<. 01); and f) schools with fewer children (<35%) participating in free/reduced price lunch programs afforded more PAO than schools with the largest participation rates (>75%) (p<. 01). Conclusions--Not only did PAO show an overall decrease across grade levels, there were substantial differences based on social class, location, and minority status. Further studies should examine: a) reasons for decrease in PAO with increased grade level; b) causes of social and geographic inequities in PAO; and c) nature of children's unstructured PA, e.g., recess. Keyword(s): exercise/fitness/physical activity, obesity issues, research