This study assessed the effect of peer tutoring on physical, instructional, and social interaction behaviors between elementary school age students with severe and multiple disabilities (SMD) and peers without disabilities. Additional measures addressed the activity time of students with SMD. The study was conducted in inclusive general physical education settings under three instructional support conditions for students with SMD: (a) teacher-directed, (b) peer-mediated, and (c) voluntary peer support. During peer-mediated and voluntary peer support conditions, the instructional and physical interaction behaviors between students with SMD and their peers increased, while social interactions remained low. The activity engagement time data increased for all target students throughout intervention sessions. Interactions between students with SMD and teachers decreased toward the end of intervention. (Contains 7 figures and 6 tables.)