Violent offending in people with intellectual disability (ID) proves to be a major challenge in the field of rehabilitation because risk-based approaches to interventions usually overlook deeply rooted psychosocial needs. The strengths-based rehabilitation model, known as the Good Lives Model (GLM), focuses on promoting personally meaningful goals and on risk management. Still, there is little evidence of its use in cases involving violent offenders with ID. This paper has discussed the efficacy of a GLM-based rehabilitation programme that is designed to address violent offenders with mild to moderate intellectual disability. The study used a mixed-methods design, and the sample comprised 48 male offenders in secure forensic ID services. The participants underwent a 12-month GLM-focused intervention that included modified offence analysis, skills development, and individualised goal planning. Violent risk (HCR-20), adaptive functioning, quality of life, and institutional incident data were measured using pre- and post-intervention measures. Qualitative interviews covered the participation and perceived change. Findings showed statistically significant change on the dynamic risk factors where mean HCR-20 clinical and risk management scores reduced by 28% during the intervention period (p < .01). Violent incidents recorded decreased to an average of 1.4 incidents per participant in the 12 months after the intervention in comparison with 3.2 violent incidences per participant 12 months before the intervention, which was a 56% decrease. There were also gains in adaptive functioning scores, with a mean increase of 19%, and self-reported quality of life improved in 72% of participants. The qualitative data revealed higher motivation and emotional regulation levels, and greater knowledge of prosocial life goals. Overall, it is possible to conclude that GLM-informed rehabilitation seems a crucial and viable method of working with violent offenders who have intellectual disabilities, and it can provide significant risk reduction and improve well-being. The results of this study endorse the use of strengths-based models in forensic ID services, alongside continued risk management activities.