Background: After several cases of peculiar hematological malignancies following introduction of new oral anti-hepatitis C virus (HCV) treatments in our recent practice, we aimed to systematically identify all cases of hematological malignancies (HM) in patients with chronic HCV infection and to compare them according to the prescription of oral anti-HCV Direct Acting Antivirals (DAA) treatment or not. Material/methods: In this single-center retrospective observational study, we included all patients with confirmed HM and chronic HCV infection managed between 2010 and 2019 in the Pitié-Salpêtrière hospital, Paris. Non-inclusion criteria were a benign hematological disorder, an HM preceding chronic HCV infection and HCV acute infection. We compared characteristics of patients who received DAA before HM diagnosis to those with no DAA before HM. Results: Over the 10 years, 61 cases of HM among HCV infected patients were identified (female 29%, median age of 58.0 years [IQR 17]). Twenty-one received DAA before the onset of HM (Group DAA+) and 40 did not (Group DAA-) including 22 having received DAA after HM. In the DAA+ group, oral NS5B, NS5A and NS3A inhibitors were used in 90, 76 and 29% respectively. HM developed in the two years following DAA initiation in 76%. Eight (38%) had Non-Hodgkin Lymphoma, 5 (24%) had an Acute Myeloid Leukaemia (AML) including two with a mixed phenotype, 2 each had Hodgkin Lymphoma, Multiple Myeloma or a myeloproliferative disorder and one each had a chronic Lymphocytic Leukaemia or AL Amyloidosis. In the Group DAA-, HM were NHL in 20(50%) patients, Myeloproliferative neoplasms in 7 (17%), Multiple Myeloma in 5, Hodgkin Lymphoma in 3, Myelodysplastic syndrome and AML in 2 (5%) each and Acute Lymphoblastic Leukaemia in one. No significant difference between the groups DAA + and - was found according to age, sex, HCV genotype, viral load, co-infection or type and exposition of previous HCV treatments. AML, liver transplantation and cirrhosis were significantly more frequent in the DAA+ group (p = 0.020, 0.045 and 0.032, respectively). Conclusion: AML seemed more frequent after using DAA treatments, notably in severe HCV patients including cirrhotic and/or liver transplanted patients. A multicentric observational study is ongoing to confirm and explore the results.