This study aims to explore differences across Greece, the UK, the USA, Malaysia, Romania, and Turkey in terms of their attitudes towards inclusive education and validate the three-model structure for attitudes towards inclusion across the above six countries. All special education teachers were administered the ATTAS-mm scale. They were employed in mainstream schools or parallel support and/or resource classes in six countries. The identified differences were interpreted regarding the effect of years of teaching experience, educational work level of teachers, and the highest degree completed across the different participating countries. Two-step cluster analysis suggested a two-cluster solution for Greece, the USA and the UK, and a three-cluster solution for Malaysia and Turkey. Finally, years of teaching experience, educational work level, and the highest degree completed had a significant effect on teachers' attitudes towards inclusion in all countries. Results are discussed for their implications in teachers training.