International discussion on inclusive education has managed to identify various contextual, process and individual factors having an impact on implementation. In addition, learning and support assistants (LSAs) have been found to be a key element in enhancing participation and learning for all students in inclusive schools. The present cross-sectional study explored the impact of assistance services on the implementation of inclusive education from the perspective of 89 Styrian LSAs and, moreover, which contextual, process and individual factors are related to their impact. The results demonstrate that assistance services are perceived as being an effective resource for the successful inclusion of students with SEN, particularly regarding their participation in field trips and their class participation. Furthermore, individual LSA characteristics were found to be crucial for inclusion success. LSAs' with higher self-efficacy or those with more comprehensive professional knowledge see their impact on the implementation of inclusive education as being more effective. Our findings highlight the value of assistance services in inclusive education and provide unique insights into aspects necessary for success. The need to promote greater professionalisation among LSAs is one key finding.