Objective: The aim of this study was to determine the predictive capacity of response at treatment week (TW) 4 for the achievement of sustained virological response 12 weeks after the scheduled end of therapy date (SVR12) to treatment against hepatitis C virus (HCV) genotype 3 (GT3) infection with all-oral direct-acting antiviral (DAA) -based regimens. Patients and methods: From a prospective multicohort study, HCV GT3-infected patients who completed a course of currently recommended DAA-based therapy at 33 Spanish hospitals and who had reached the SVR12 evaluation time-point were selected. TW4 HCV-RNA levels were categorized as target-notdetected (TND), below the lower limit of quantification (LLOQTD) and >= LLOQ. Results: A total of 123 patients were included, 86 (70%) received sofosbuvir/ daclatasvir +/- ribavirin, 27 (22%) received sofosbuvir/ ledipasvir/ ribavirin and 10 (8.1%) received sofosbuvir/ ribavirin, respectively. In all, 114 (92.7%) of the 123 patients presented SVR12 in an on-treatment approach, but nine (7.3%) patients relapsed, all of them had presented cirrhosis at baseline. In those who achieved TND, LLOQTD and >= LLOQ, SVR12 was observed in 81/83 (98%; 95% CI 91.5%-99.7%), 24/28 (85.7%; 95% CI 67.3%-96%) and 9/12 (75%; 95% CI 42.8%-94.5%), respectively; p(linear association) 0.001. Corresponding numbers for subjects with cirrhosis were: 52/54 (96.3%; 95% CI 87.3%-95.5%), 14/ 18 (77.8%; 95% CI 52.4%-93.6%) and 7/10 (70%; 95% CI 34.8%-93.3%); p 0.004. Conclusions: TW4-response indicates the probability of achieving SVR12 to currently used DAA-based therapy in HCV genotype 3-infected individuals with cirrhosis. This finding may be useful to tailor treatment strategy in this setting. (C) 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.