A recent study led by the Department of Medicine, School of Clinical Medicine, LKS Faculty of Medicine of the University of Hong Kong (HKUMed), in collaboration with the Correctional Services Department, has demonstrated that mass screening for hepatitis C virus (HCV) infection among persons in custody (PICs) is a cost-effective strategy. By enabling early identification and treatment of infected PICs, this approach can offer measurable health benefits. The data provide strong evidence to support the implementation of systematic prison-based HCV screening in Hong Kong. The findings are published in The Lancet Regional Health—Western Pacific.