Screening of Hepatitis C virus (HCV) infection by molecular test is not routinely performed for the care of human immunodeficiency virus (HIV) infected patients in most countries of Sub-Saharan Africa such as Benin. The aim of this study was to assess the extent of HCV infection in patients infected with HIV in Cotonou. This study was conducted from February to June 2017 on HIV infected patients from the National Reference Center for Research and Management of HIV infection in Cotonou. Blood samples were collected from patients to detect anti-HCV antibody and HCV viral load. A total of 205 patients were tested, out of which 67.3% were females. Seroprevalence of anti-HCV antibody was 7.8% and HCV viral load was detectable in 3.4% of cases with a median of 2.200.000 IU/mL (6.3 Log 10 ). Three out of seven patients (42.8%) had negative HCV serology with positive HCV RNA detection. In conclusion, the prevalence of HCV infection among HIV infected patients is not negligible in Cotonou. Universal access to molecular tests is needed in the country to detect HCV infection in these patients.