A project is described in which students with severe disabilities from a self-contained day school were successfully integrated into a program within the main building of a regular campus which included limited participation in a regular fourth grade classroom. The project was initiated after various preparations were made, including building adaptations, such as provision of access for walkers and wheelchairs; faculty preparation, including discussion of expectations and introduction of the special education faculty; and student preparation, including discussions of mental retardation and the rationale and benefits of the project as well as fears and concerns. The project involved instituting a fourth grade partnering class in which nonhandicapped students who volunteered to be"partners" to their handicapped peers assumed such responsibilities as selection of reading materials, helping with lunch, assisting with art and music, participating in language-building activities, and planning activities. Activities took place in both classrooms with participation of regular and special education teachers. The paper emphasizes the roles of university personnel, special education administration, elementary counselors, regular classroom teachers, and special education teachers. Appendices provide training materials for teachers and students, measures of student attitudes before and after the project, a mainstreaming activity list, and suggestions for modifying instruction for the special education student. The document contains seven references. (BRM)