BACKGROUNDIn the last few years we have witnessed a revolution in the treatment of hepatitis C virus (HCV) infection. With the introduction of direct-acting antiviral agents (DAAs), sustained virological response (SVR) is achieved in more than 95% of the patients. The focus is now being turned to the global targets set by the World Health Organization, with the aim of achieving HCV elimination by 2030. Prison inmates constitute one of the high-risk groups, and receive treatment less frequently due to several barriers in access to health care.AIMTo describe the management and follow-up of a cohort of HCV monoinfected patients treated with DAA in the prison setting, where tertial referral liver center specialists locally provide, on-site assessment and treatment for the prisoners.METHODSA prospective observational study was conducted from April 2017 to March 2020, which included all HCV monoinfected prison inmates in the largest Northern Portugal prison. Demographic, clinical, and laboratory data, as well as transient elastography measurements, were collected onsite by the medical team and prospectively recorded. Patients were treated with DAA according to international guidelines. The primary endpoint was SVR at post-treatment week 12. RESULTSThere were 98 monoinfected HCV male inmates (mean age, 42.7 ± 8.6 years) included in the analysis. Injecting drugs or tattooing were reported in 74.5%, with 38.8% of the latter being done in prison. Alcohol consumption of more than 30 g/d was referred in 69.4%. The most prevalent genotype was 1a (54.1%), followed by 3 (27.6%), 4 (9.2%) and 1b (6.1%). Pretreatment fibrosis degree was mild-to-moderate (F0-F2) in 77.6% and severe in 22.4% (F3-F4). Treatment regimens chosen were: 45.9% elbasvir/grazoprevir, 29.6% sofosbuvir/velpatasvir, and 12.2% sofosbuvir/ledispavir and glecaprevir/pibrentasvir. No major adverse events were observed. SVR at post-treatment week 12 was 99%.CONCLUSIONIn a population considered to be both hard-to-access and a cornerstone for HCV elimination, the onsite evaluation and treatment of HCV-infected prisoners, achieved an exceptional highly effective success rate. This type of collaborative program should be considered to be expanded, to support hepatitis C elimination efforts.