Children with autism spectrum disorder (ASD) have been shown to benefit from parent-implemented interventions (PIIs). This meta-analysis improved on prior reviews of PIIs by evaluating RCTs and multiple potential moderators, including indicators of research quality. Fifty-one effect sizes averaged moderately strong overall benefits of PIIs (g = 0.553), with studies having lower risk of research bias yielding lower estimates (g = 0.47). Parent and observer ratings yielded similar averaged estimates for positive behavior/social skills (g = 0.603), language/communication (g = 0.545), maladaptive behavior (g = 0.519), and to a lesser extent, adaptive behavior/life skills (g = 0.239). No other study, intervention, or participant characteristic moderated outcomes. PIIs with children with ASD tend to be effective across a variety of circumstances.