The purpose of this study was twofold: (a) to examine and compare levels of parental self-efficacy (PSE) and parenting practices (PP) between parents of young children with and without disabilities regarding physical activity (PA) participation of their children and (b) to analyze and compare the relationship between PSE and PP. A total of 235 participants completed a survey measuring levels of PSE and PP related to the promotion of PA for their children. The results showed no differences in levels of PSE and PP between parents of children with and without disabilities (p > 0.05). A positive moderate relationship was found between PSE and PP from total participants (r = 0.497, p < 0.001) as well as parents of children with disabilities (r = 0.440, p < 0.001). Parents of children with disabilities had comparable levels of confidence (PSE) and competence (PP) in promoting PA to their children compared to those of parents of children without disabilities. The current study supports the mechanism of self-efficacy and behavior and the importance of early intervention for parents of children with disabilities to build higher PSE for their child’s future PA habit through improved PP.