The primary aim of this review was to identify and evaluate the strength of associations of the key parental factors measured in studies examining early childhood physical activity (PA). A systematic review of the literature, using databases PsychINFO, Medline, Academic Search Complete, PSYCHinfo, and CINHAL, published between January 1986 and March 2011 was conducted; 20 papers were relevant for the current review. While 12 parenting variables were identified, only 5 of these had been investigated sufficiently to provide conclusive findings. There were inconsistencies in the findings involving the social learning variable parental enjoyment and variables involving parental behaviours such as maternal depression and self-efficacy, and rules for sedentary behaviour, and parental perceptions, which included perceived importance of PA, fear of safety, and perception of child's motor competence. Given these inconsistencies, a meta-analysis was conducted to determine whether the method of measuring PA (objective or subjective) influenced the strength of associations between the parental factors and young children's PA. There was no difference in the strength of associations in the studies that used objective or subjective measurement (via parent self-report). Further investigation is needed to clarify and understand the specific parental influences and behaviours that are associated with PA in young children. In particular, longitudinal research is needed to better understand how parental influences and PA levels of children during the formative preschool and early elementary school years are associated. (Contains 6 tables.)