INTRODUCTION: Regular physical activity (PA) in children is associated with several health benefits, but a majority of children do not achieve the recommended amount of PA. Research suggests that parent involvement in PA predicts greater child PA. Research on other predictors of child PA, such as parent encouragement and parent conversations with their child about PA have evidenced contradictory findings. PURPOSE: This study examined 1) whether more parent involvement in child PA predicts greater child PA; 2) whether more parent conversations with their child about PA predicts greater child PA; 3) whether parent concern for child weight influences the relationship between either parent involvement in child PA, or parent conversations with their child about PA, and child PA. METHODS: Child participants (n=98, 39% female, M-Age=12, M-BMI=23.0) wore an activity monitor for 7 days. A parent of each child completed self-report measures of parent conversations with their child about PA, parent concern for child weight and parent involvement in child PA (i.e. engaging in PA with child or helping child engage in PA). Regression analyses were conducted to examine whether parent conversations with their child about PA or parent involvement in child PA predicted child PA. Moderation analyses were conducted to examine if parent concern for child weight influenced the relationship between parent conversations with their child about PA or parent involvement in child PA and child PA. Analyses included the covariates age, sex, child BMI and whether a sibling participated in the study. RESULTS: Parent involvement in child PA predicted child PA; greater involvement in child PA predicted greater child PA (F(5,92)=3.57, p=0.01, R2 Δ=0.09). Parent conversations with their child about PA did not predict child PA. Parent concern about child weight did not modify the relationship between parent conversations with their child about PA or parent involvement in child PA and child PA. CONCLUSIONS: Consistent with previous research, parent involvement in child PA supports a child’s engagement in PA. Future research should examine factors that may explain the relationship between parent involvement in child PA and child PA, such as different means of parent engagement or characteristics of the child (e.g., child temperament or parenting style).