Household pets can have a positive influence on quality of life for individuals who live with them (Bryant, 1990). Little previous research has investigated issues related to interaction between individuals with developmental disabilities and pets. In this study, we used simple behavioral intervention procedures to decrease pet mistreatment by a young child with autism. Specifically, differential reinforcement of alternative behavior (DRA) and differential reinforcement of other behavior (DRO) were evaluated. DRA did not decrease the behavior but DRO produced immediate and significant decreases in pet mistreatment and the DRO interval was successfully lengthened to 10 min. All sessions were implemented by the child's regular behavioral therapy team, in the child's home. (Contains 1 figure.)