The purposes of this study were to (a) determine children's and parent's physical activity patterns, (b) determine whether children's own beliefs about physical activity are related to their perceptions of their parent's beliefs about physical activity, and (c) examine the relationship between children's beliefs about physical activity and their own physical activity patterns. Forty-five 8-10 year-old children and their parents (n=135) wore Biotrainer accelerometers for seven consecutive days. Additionally, children completed Brustad's (1996) modified Children's Attraction to Physical Activity (CAPA) questionnaire and parent's completed a short demographic questionnaire. Multiple regression revealed children's and parent's activity patterns were not significantly correlated. A multivariate regression analysis determined children's own beliefs about physical activity are not significantly related to their perceptions of their parent's beliefs about physical activity. One subscale, parental encouragement, however, was significantly related to children's beliefs about physical activity. This finding indicates that parents who encourage their children to be involved in physical activities, regardless of their own physical activity behavior and beliefs, appear to have more of an influence on their children's beliefs of the importance of physically activity. Finally, a multiple regression with children's activity as the dependent variable was used to test the relationship between children's beliefs and their physical activity patterns; it was not significant. Findings from this study suggest that the mechanisms underlying parental influence on children's physical activity may be much more complex since they did not appear to involve beliefs or behavior as determinants; a systemic approach may be useful to guide further research in this area.