BackgroundHepatitis C virus (HCV) infection is a key cause of liver disease but can be cured in more than 95% of patients. Around 70 000 people in England may have undiagnosed HCV infection and many more will not have been treated. Interventions to increase case-finding in primary care are likely to be cost-effective; however, evidence of effective interventions is lacking. The Hepatitis C Assessment Through to Treatment (HepCATT) trial assessed whether a complex intervention in primary care could increase case-finding, testing, and treatment of HCV.AimTo investigate the feasibility and acceptability of the HepCATT intervention.Design and settingA qualitative study with primary care practice staff from practices in the south west of England taking part in the HepCATT trial.MethodSemi-structured interviews were carried out with GPs, nurses, and practice staff to ascertain their views of the HepCATT intervention at least 1 month after implementing the intervention in their practice. Normalisation process theory, which outlines the social processes involved in intervention implementation, informed thematic data analysis.ResultsParticipants appreciated the HepCATT intervention for increasing knowledge and awareness of HCV. Although some initial technical difficulties were reported, participants saw the benefits of using the audit tool to systematically identify patients with HCV infection risk factors and found it straightforward to use. Participants valued the opportunity to discuss HCV testing with patients, especially those who may not have been previously aware of HCV risk. Future implementation should consider fully integrating software systems and additional resources to screen patient lists and conduct tests.ConclusionWhen supported by a complex intervention, primary care can play a crucial role in identifying and caring for patients with HCV infection, to help stem the HCV epidemic, and prevent HCV-related illness.