In the present case study, ball-throwing skills were taught to a boy with Asperger's disorder, and secondary benefits for him from that experience were examined. The teaching program was based on applied behavior analysis. After a task analysis that divided overhand ball-throwing behavior into 10 behavior units, training utilized visual stimulus prompts and a chaining procedure, in a changing criterion design. The results showed that, although it took some time to achieve, all the behavior items were learned, so that the boy acquired skills necessary for ball throwing. The present study confirms the effectiveness of prompts using picture cards and behavioral coaching. It was difficult to maintain the boy's motivation for the prolonged training, although verbal interaction may be effective to increase motivation. Secondary effects observed included increased social interaction and a more proactive attitude towards exercise, behaviors that were not goals of the teaching program. Such effects may indicate potential benefits of the acquisition of sports skills as one component of leisure activities of children with developmental disorders.