A description of the Social Exchange Laboratory's work with autistic children is presented. The laboratory's philosophy of the exchange theory of autism, seen as a set of habitual response patterns maintained and intensified by exchanges which are inadvertantly structured by others in the child's environment, is set forth with characteristics, examples, patterns and therapy considerations for the autistic child included. Exchange therapeutic procedures which reverse or replace the fundamental autistic habit patterns are developed around seven stages; food is initially used as a powerful reinforcer as the child progresses through them. The procedures and reports of these techniques as used in the laboratory are expanded and described with case histories, therapist procedures and exchanges between the therapist, child and parent. (WW)