A growing disparity between the mental health needs of children and their lack of treatment served as the basis of this study. To address this existent gap, I proposed that child-centered play therapy (CCPT), a holistic treatment that fosters children's emotional, developmental, and social growth would serve as a viable treatment. The purpose of this study was to examine the effect of CCPT on problem behaviors among children identified with an intellectual disability. Specifically, a single case, A-B-A design (N = 2) was used to examine changes in participant's problem behaviors as measured on the Aberrant Behavior Checklist (ABC) across conditions. Trained raters used the ABC to rate participant's problem behaviors 3 times per week during the course of this study. Participants completed 2 weeks of a no-intervention phase, 5 weeks of play therapy 3 times per week, and 2 weeks of a no-intervention maintenance phase. Additionally, participants were administered the Gesell Developmental Observation to assess their maturational age during the baseline and maintenance phases. Parents also completed the ABC during two intervals: baseline phase, and maintenance phase. Analysis of results indicated that problem behaviors decreased for both participants. Results from the percent of non-overlapping data (PND), an indice for effect size further revealed that play therapy was a very effective treatment for participants. Follow-up interviews suggested that play therapy is a viable intervention for children with intellectual disabilities and problem behaviors. Clinical observations and implications for future research are presented. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]