Research on the impact of the Project Approach on young children with disabilities or children who are at-risk is limited. Mixed methods were used to study the impact of the Project Approach on the social interactions, challenging behaviors, and language development of eight focal children in two inclusive classrooms. Child participants were two children with IEPs and two children identified as at-risk from each class. Adult participants were six professionals who received high quality supports to implement the Project Approach. Adults were interviewed prior to the beginning of the study and again mid-, and post-implementation. Choice time observations were videotaped twice per week over 14 weeks to assess the impact of the Project Approach on play levels and MLU[subscript m]. Results revealed that social interactions, challenging behaviors, vocabulary, MLU[subscript m], were positively impacted following implementation of the Project Approach. Limitations of the study and suggestions for research and practice are discussed. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]