Background: This paper reports quantitative and qualitative follow-up data from three participants who attended a Dialectical Behaviour Therapy (DBT) group for people with an intellectual disability. Materials and Methods: Quantitative data regarding psychological well-being, psychological distress (measured using the Psychological Therapies Outcome Scales; PTOS) and quality of life (measured using the Health of the Nation Outcome Scales--Learning Disability; HONOS-LD) are reported for pre-group, post-group and at 6-month and 2-year follow-up. Interviews were conducted with participants post-group and at 2-year follow-up. Data were analysed using thematic analysis. Results: Improvements in scores on measures of psychological well-being, psychological distress and quality of life appear to be maintained at 6-month follow-up, but scores at 2-year follow-up suggest a return to baseline. Qualitative self-report data suggest a number of interesting ways participants adapted and individualised techniques from the group, as well as suggesting possible barriers to maintaining change in the longer term. Conclusions: Clinical implications are considered to improve effectiveness of similar interventions, as well research implications in order to improve knowledge about the longer term impact of group DBT interventions.