Evidence of the effectivity of play-based interventions in children with autism spectrum disorder (ASD) was evaluated by PRISMA-based literature study and a Risk of Bias (RoB) assessment. Many of the 32 eligible randomized controlled trials (RCT) reported improved social interaction, communication, daily functioning and play behaviour. They also reported decreased problem behaviour, better parental attunement and parent-child interaction. We assessed 25/32 of the RCTs with high RoB, mainly related to homogeneity of the study population, lack of power, and performance bias. We concluded with due care that the effectivity of play-based interventions differed across RCTs, most reported improvements are found in ASD symptoms, everyday functioning, and parental attunement. In future research, findings should be replicated, taking account of the RoB.