Quite a few studies have addressed the academic learning development of students with and without special educational needs in inclusive schools (Kocaj, Kuhl, Kroth, Pant & Stanat, 2014). However, emotional well-being in school (Rauer & Schuck, 2003), the feeling of being integrated (Venetz, Zurbriggen & Eckhart, 2014), and attitudes towards students with special educational needs (Bossaert, Colpin, Pijl & Petry, 2011) are also important factors for social participation and successful inclusion (Schwab, 2015a). The aim of the ATIS-STEP study is to analyze the attitudes towards and beliefs about inclusive education of teachers, parents and students in Austria. Especially interesting are the interactions between opinions of teachers, parents and students. We search to identify factors that are particularly relevant for the development of an intervention program.