The purpose of this study was to determine the effectiveness of a 10 week water exercise swimming program (WESP) on the aquatic skills and social behaviors of 16 boys with autism spectrum disorders (ASDs). In the first 10 week phase (phase I), eight children (group A) received the WESP while eight children (group B) did not. A second 10 week phase (phase II) immediately followed, with the treatments reversed. Both groups continued their regular treatment/activity throughout the study. Improvements were seen in aquatic skills for both groups subsequent to the WESP. Following phase I, significant social improvements were seen in group A. Following phase II, social improvements were seen for group B, whereas group A merely maintained the improvements they attained through the implementation of the WESP during phase I. Results indicate that the WESP improved aquatic skills in the participants, and holds potential for social improvements. (Contains 7 tables and 1 figure.)