Chronic hepatitis C virus (HCV) infection is not uncommon in patients with acute leukemia due to frequent blood transfusions. The treatment of HCV in patients with acute leukemia can produce profound immune dysfunction with the risk of severe cytopenia. We report the case of a young man who was treated with combined therapy of peginterferon α 2a and ribavirin for HCV while he was on maintenance anti-leukemic treatment. The patient required reduction in the dose of peginterferon α 2a and the addition of filgrastim due to neutropenia. Therapy for HCV was continued for 72 weeks and at the end of therapy, the patient had undetectable HCV RNA. The patient maintained a sustained viral response two years after the end of therapy and developed complete remission of leukemia, whereupon his anti-leukemic therapy was also discontinued. We recommend conducting further large prospective studies in HCV patients treated for leukemia to determine the safety and efficacy of antiviral therapy in this group of patients.