AbstractSocial problem-solving training has been successful in improving maladaptive behaviour and problem-solving skills for individuals with intellectual disability. However, in contrast to individuals without intellectual disability there has been only one study that has examined whether social problem-solving training can improve psychological distress in individuals with intellectual disability and a psychiatric diagnosis. Three participants from a vocational community centre with mild intellectual disability, comorbid mental illness, and challenging behaviour, participated in 15 individually delivered sessions of social problem-solving training. Social problem-solving skill, behaviour, and psychological distress measures were used to assess outcome. All three participants showed improvement in social problem-solving skills, and two participants showed improvement in depression. Improvement was maintained at 4-week follow-up. The results provide preliminary evidence that social problem-solving training could be an effective intervention tool for the treatment of psychological distress in individuals with mild intellectual disability.