Background: Parenting children with neurodevelopmental disorders and intellectual disabilities is associated with psychological and health problems in parents. It is also related to authoritarian and inflexible parenting, hindering the psychological adjustment of diagnosed children. Contextual therapies are developing a promising line of intervention for parents of children with intellectual disabilities. Aim: To present a protocol for psychological flexibility in parents and its effect, aimed at reducing the impact of raising a child with a disability. Methods: Standardised questionnaires and self-monitoring at pre, post, and at follow-up were administered to assess psychological changes after the intervention. Results and Conclusions: Intervention was followed by an increase in general health and a decrease in psychological inflexibility, private eventsuppression, and parental stress at follow-up. An increase in supportive interactions and a decrease in punitive interactions were observed. Training parents in psychological flexibility may improve the adjustment of parents and children with intellectual disabilities.