The preparation of teachers for regular schools has clearly needed to undergo quite significant change in recent years. One major adjustment has been the necessity to prepare teachers for progressively more diverse student populations as they will increasingly be required to teach in inclusive classrooms. Many teacher education institutions are, therefore, offering units of work that aim to tackle this. Utilizing an international data set of 603 pre-service teachers, consideration is given to the effect of a range of demographic differences on changing pre-service teacher attitudes toward inclusion; sentiments towards people with a disability and in reducing their concerns about inclusion when involved in a focused unit of work. Pre- and post-training comparisons are made which identify a range of variables that impact on changing pre-service teacher perceptions about inclusion. The discussion focuses on the importance of differentiating teacher preparation courses to address these different needs of pre-service teachers. [Copyright of International Journal of Inclusive Education is the property of Routledge. Full article may be available at the publisher's website: http://dx.doi.org/10.1080/13603110701365356]