This study aimed to assess the psychometric properties of a child-report, multidimensional measure of physical activity (PA) parenting, the Activity Support Scale for Multiple Groups (ACTS-MG), in African American and non-Hispanic white families. The ACTS-MG was administered to children aged 5 to 12 years. A three factor model of PA parenting (Modeling of PA, Logistic Support, and Restricting Access to Screen-based Activities) was tested separately for mother's and fathers' PA parenting. The proposed three-factor structure was supported in both racial groups for mothers PA parenting and in the African American sample for fathers PA parenting. Factorial invariance between racial groups was demonstrated for mother's PA parenting. Building on a previous study examining the ACTS-MG parent-report, this study supports the use of the ACTS-MG child-report for mothers PA parenting. However, further research is required to investigate the measurement of fathers PA parenting across racial groups.