Expanding interests may be a behavioral cusp, resulting in widespread changes across skills, and therefore is particularly relevant in intervention programs for children with autism. Little research has addressed directly increasing the diversity of activities and interests for this population. This study describes a program developed to increase activities and interests in a girl dually-diagnosed with pervasive developmental disorder (PDD-NOS) and Downs syndrome (DS). A multiple-baseline design across stimuli was employed to evaluate the program. The results show that the program increased number of total and different toy interactions. No effects were observed for overall duration of toy interactions. Results are discussed in relation to play skill instruction and preference assessment literature, the cusp, and autism intervention programs.