To increase participation in physical activity, it is important to understand the factors associated with a child’s choice to be physically active or sedentary. The neighborhood and home environments may be related to this choice. To determine whether the neighborhood environment or number of televisions in the home environment are independently associated with child physical activity and television time. The associations of the neighborhood and home environments on active and sedentary behaviors were studied in 44 boys and 44 girls who wore accelerometers and recorded their television watching behaviors. Neighborhood environment variables were measured using extensive geographic information systems analysis. Hierarchical regression analyses were used to predict physical activity after controlling for individual differences in age, socioeconomic status, percentage overweight, and time the accelerometer was worn in Step 1. Sex of the child was added in Step 2. A neighborhood design variable, street connectivity, accounted for an additional 6% (p <or= .01) of the variability in physical activity in Step 3. A block of variables including a measure of neighborhood land use diversity, percentage park area, and the interaction of Percentage Park Area x Sex then accounted for a further 9% (p <or= .01) of the variability in physical activity in Step 4. Increased access to parks was related to increased physical activity in boys but not in girls. The number of televisions in the home accounted for 6% (p <or= .05) of the variability in television watching behavior. Neighborhood environment variables did not predict television watching that occurs in the home. The neighborhood environment is more strongly associated with physical activity of boys than girls. Sedentary behaviors are associated with access to television in the home environment. To promote physical activity in children, planners need to design environments that support active living and parents should limit access to television viewing in the home.