Self-determination is considered to be a basic human right which, to develop, demands contextual opportunities as well as individual competencies. For people with intellectual and developmental disabilities, the family is the natural support environment in the task of increasing control over their own lives. There is little, however, that has been published in Spain on the needs and strengths of families in this regard. This article presents a study carried out in Spain on the knowledge, attitudes and strategies that a sample group of parents (N = 201) have regarding self-determination. An analysis of the data gathered highlights the need for intervention proposals to prepare parents to further their children's self-determination, through collaborative partnerships and through cognitive restructuring.