Meta-analysis was used to integrate research on the relations between parental socialization behavior and child and adolescent physical activity (PA) levels. Four major databases were examined: PubMED, ERIC, Web of Science, and PsychLit (1960-2005). Thirty studies met the following inclusion criteria:(a) child age (2-18 years) and (b) statistical information permitting calculation of an effect size between parent socialization behavior and child PA. Mean age of participants across studies ranged from 2.54 to 15.5 years. The unweighted mean and median effect sizes (as indexed by r) were. 17 and. 13, respectively, indicating that a moderate positive relation exists between parental support and modeling behavior and child and adolescent PA levels. The moderating effect of type of parental socialization behavior, population characteristics, and methodological factors were investigated. Theoretical and methodological implications concern the inclusion of mediated models of parental influence and the use of longitudinal investigations in determining causal direction. From an applied viewpoint, these results are useful for the design of future, more effective childhood obesity prevention programs by suggesting child-age-appropriate parental influences.(PsycINFO Database Record (c) 2016 APA, all rights reserved)