Accessible summary Mindfulness helps people focus instead of worrying about the past or future. We talked to six people who took part in a mindfulness group. They all had intellectual disabilities and were in hospital for mental health problems. They told us the group helped, and we hope that mindfulness can help other people too. Summary The study focused on the effectiveness of group mindfulness for people with intellectual disabilities in an assessment and treatment unit. Six participants with mild or moderate intellectual disabilities were interviewed using semi‐structured interviews. The interviews focused on identifying the benefits and difficulties of using mindfulness. The interviews were analysed using thematic analysis. Five themes were identified which were categorised into interpersonal (‘helping people’) and intrapersonal (‘focusing on one particular thing’; ‘improving skills’; get rid of all nasty bad stuff you want to get rid of’) benefits. The theme ‘bit too late to teach old dog new tricks’ captured the difficulties encountered. The themes highlighted that people with intellectual disabilities were able to form an understanding of mindfulness and were able to benefit from the intervention.