This study examined the treatment efficacy of "PEERS"® (Program for the Education and Enrichment of Relational Skills) among Chinese adolescents with autism spectrum disorder (ASD) in Hong Kong. The original "PEERS"® manual was translated into Chinese, and cultural adjustments were made according to a survey among 209 local adolescents in the general population. 72 high-functioning adolescents with ASD were randomly assigned to a treatment or waitlist control group. The 14-week parent-assisted training significantly improved social skills knowledge and social functioning, and also reduced autistic mannerisms. Treatment outcomes were maintained for 3 months after training and replicated in the control group after delayed treatment. The present study represents one of the few randomized controlled trials on "PEERS"® conducted outside North America.