Despite widespread clinical use of group-based social skills training (SST) for children with autism spectrum disorder (ASD), there remains a lack of follow-up data, generalisation effects, common definition of social skills, and teacher report data. This study evaluated the effectiveness of an 8-week SST intervention with a play component (unstructured versus semi-structured) for children with ASD across a range of social, behavioural and emotional measures. Forty-five children aged 8-12 years (M = 10.16, SD = 1.26) were assigned to one of three groups: (a) SST with unstructured play; (b) SST with semi-structured play; and (c) waitlist control. Compared to a waitlist control group, children who participated in the SST intervention showed significant gains in social skills and social competence over time.