BackgroundWorldwide, binge drinking (BD) today follows being a public health concern among adolescents. This study sought to assess the cost-effectiveness and cost-utility of a web-based computer-tailored intervention to prevent BD in adolescence.MethodsThe sample was drawn from a study evaluating the Alerta Alcohol programme. The population consisted of adolescents aged 15–19. Decision tree analysis was used to estimate costs and health outcomes, as measured by number of BD occasions and quality-adjusted life years (QALYs). Incremental Cost-Effectiveness and Cost-Utility Ratios were also calculated from National Health Service (NHS) and societal perspective and for a time horizon of four months. Multivariate deterministic sensitivity analysis of best/worst scenarios by subgroups was used to account for uncertainty.ResultsThe intervention was dominant from the societal perspective resulting in savings of €7,986.37 by one BD occasion averted per month. With regard to Incremental Cost-Utility Ratios, the intervention resulted in an incremental cost of €71.05 per QALY gained from NHS perspective and this was dominant, from societal perspective, resulting in savings of €34,126.64 per QALY gained in comparison with the control group. Subgroup analyses showed that the intervention resulted dominant for girls from both perspectives, and for those who were older (17 years or more) from NHS perspective.ConclusionComputer-tailored feedback is a cost-effective way to reduce BD and to increase QALYs among adolescents. However, long-term follow-up would probably be needed to capture major changes both in reduction of BD and in increasing of health-related quality of life.Trial registration(ClinicalTrials.gov): NCT03288896. Registration date: September 20, 2017. “Retrospectively registered”.