Introduction This paper explores the experiences of staff working on a sex offender treatment programme for people with a learning disability. This area has not previously been the subject of research. Method Semi-structured interviews were carried out with eight participants working on a treatment programme for sex offenders with a learning disability. Interviews were transcribed and analysed using Interpretative Phenomenological Analysis. Results Four superordinate themes emerged from the data: rewards and motivation; the challenge of effecting change; the personal impact of work; and ways of managing the impact of work Conclusions The results suggest that working on the treatment programme is a complex and challenging experience. Participants both shared and had distinct ways of meeting the challenges of work and this had an impact on the process of effecting change with group members and their own well-being – these issues were reflected in relation to the themes of empathy and humour.