A critical aspect of inclusive policies and practices is the role that Teacher Assistants (TAs) are supposed to assume within mainstream classrooms. Despite the evidence, TAs are still linked to the most vulnerable children, especially those with severe afflictions. This exploratory mixed method of investigation analyses the differences between the job requirements standardised by the Catalan Government (Spain), the roles the TAs believed they had been hired to perform and the tasks they were really carrying out in their schools. It includes teacher and union representative experiences to obtain a more holistic view of current practices. This article provides TAs’ experiences in the Catalan context as well as an analysis of the legal framework on the matter; to better understand these agents, putting emphasis on inclusive practices. According to standards, only one type of TA should give educational support, the others should merely assist. The findings highlight the importance of real and coherent inclusion-oriented TA roles. This places the TA as a key member of a support network maximising all learning opportunities.