The effectiveness of a range of psychological models adapted for use with people with intellectual disabilities has been well documented. A number of studies have used qualitative methods to examine people with intellectual disabilities’ experiences of these adapted interventions. Such research is important for identifying service users’ views on the helpful and challenging aspects of psychological interventions to ensure they meet the needs of people with intellectual disabilities. To consolidate this research, a systematic review using a metaethnographic approach was undertaken. A systematic search identified sixteen relevant studies. These studies were reviewed, critically appraised and key themes were extracted. Five key concepts were identified: adapting to therapy, the therapeutic environment, group dynamics, the therapeutic relationship and the impact of therapy on life. Clinical implications and limitations are discussed. In particular, the review highlights the need for further consideration of power differentials within the therapeutic relationship and further adaptations to ensure accessibility of therapy for people with intellectual disabilities.