This study examined the effect of a 12-week fundamental movement skills (FMS) intervention on the motor skills of 20 boys with autism spectrum disorder (ASD) (ages 3-10 years) in an Asian country and whether the intervention effect would persist for at least 12 weeks after the intervention. In Part I, 10 boys with ASD (Group 1) received the intervention, whereas the remaining 10 boys with ASD (Group 2) did not (true control, no intervention). The arrangement was reversed in Part II. The main findings were that children in both the ASD groups exhibited significant improvements in the overall gross motor development and the locomotor and object control subtest scores after the intervention. The effectiveness appeared to be sustained for at least 12 weeks in Group 1. The study findings indicate the importance of including FMS programming as a part of the early intervention services delivered to young children with ASD.