Introduction The use of Special Needs Assistants (SNA) is the primary system of support used in Ireland for the successful inclusion of children with Special Educational Needs (SEN) in mainstream schools (Department of Education and Skills 2011). Research has frequently suggested that physical education (PE) teachers have concerns with facilitating the inclusion of students with SEN (Sweeney and Coulter 2008). This research explores the current and desired role of SNAs in PE in mainstream post-primary school. Methods This study employed a mixed methods approach using questionnaires (n=523), and focus groups and interviews (n=11). Results and Discussion As has been found in existing research there were major discrepancies between the prescribed circular role of the SNA and the duties they were fulfilling in schools, with duties of a teaching nature being very prevalent. The role of SNAs in PE was found to be predominantly an active one, with both PE teachers and SNAS perceiving the role to be important and expressing a desire for SNAs to be increasingly active in PE. The individual nature of SEN had a statistically significant impact on the roles fulfilled by SNAs in PE, and in general education, along with students’ inclusion in PE. Other factors found to significantly impact on the role of the SNA were the people responsible for delegating duties and the years of working experience and gender of the SNA and PE teacher. The implementation and communication of the PE curriculum was highlighted as impacting on the inclusion of students with SEN in PE and also on the SNAs role in PE. Finally it was ascertained that SNAs were not adequately trained to be fulfilling many of the duties which they currently were in PE and in general education and desired more training opportunities