ObjectivesThe economic burden of incarceration is substantial in Australia. People released from prison are at high risk of poor health and this is an important predictor of recidivism. The ‘Passports Study’ was a randomised controlled trial of an intervention designed to increase health service utilisation after release from prison. The aim of this study is to conduct a cost–utility analysis of this transitional programme.SettingAustraliaDesignA hybrid simulation model was developed to estimate the changes to total economic costs and effectiveness expressed as quality-adjusted life-years (QALYs) from the adoption of the ’Passports’ intervention compared with the control group. Model parameters were informed by linked data from Queensland Corrective Services, Medicare, Pharmaceutical Benefits Scheme, Queensland Hospital Admission Patient Data Collection, Emergency Department Information System and National Death Index. Health-related quality of life was measured using the Short-Form 8 Health Survey (SF-8). The primary outcomes were the costs and estimated QALYs associated with the intervention group and the control group. Probabilistic sensitivity analysis was conducted to test parameter uncertainties.ResultsCompared with the control group where no attempt was made to encourage health service utilisation, an average participant in the intervention group incurred an extra cost of AUD 1790 and experienced slightly reduced QALYs, which indicated that the intervention was dominated in the baseline analysis. Probabilistic sensitivity analysis revealed that the transitional programme had a low probability of being cost-effective with the outcome measures selected.ConclusionThe findings of this study do not provide economic evidence to support the widespread adoption of the Passports intervention. Due to the reductionist nature of the cost–utility approach, it may be that important health-related benefits have been omitted. Another research approach using a wider range of health-related measures might generate different conclusions.