Research in the field of disability have stressed self-determination as a key construct, both at the individual level, because of its impact on quality of life, and at the organisational level, as it stands as a fundamental concept for programmes and services design. As the construct comprehension and attributed importance may influence professionals' practices, this study aims to explore professionals' beliefs and knowledge about self-determination, and align them with the newest theoretical framework. Four discussion groups were held with professionals (teachers and educators working with adults) that were analysed through thematic analysis, obtaining a total of 21 indicators. Results indicate that professionals are familiar with many of the more specific self-determination components. Professionals comprehension of the construct is fairly aligned with the newest theoretical framework, although greater abstraction is needed to embrace the whole model complexity. Finally, the implications raising how professionals' perspectives contribute to the promotion of self-determination of people with intellectual disability are discussed, and future lines of research are outlined.