Immune thrombocytopenic purpura (ITP) is a life-threatening complication following pegylated interferon alpha (PEG-IFN) plus ribavirin treatment, the standard treatment for hepatitis C virus (HCV) infection. We reported a rare case with late-onset ITP after withdrawal of PEG-IFN treatment.A 53-year-old male with hepatitis C developed massive gum bleeding and a severe, reversible, immune thrombocytopenia 2 weeks after cessation of PEG-IFN treatment for HCV due to anemia and depression. The platelet count decreased to 4000 cells/μL. The HCV viral load was undetectable at the end of PEG-IFN treatment and during follow-up for 5 months. Other potential autoimmune disorders were ruled out. Late-onset ITP associated with PEG-IFN treatment was diagnosed.The patient was treated successfully with steroid and azathioprine. Platelet count gradually increased to 117 × 10 cells/μL on the 18th day after admission.ITP is a rare complication in patients with hepatitis C or in patients who received PEG-IFN treatment. The particular case supported that it may occur even after withdrawal of PEG-IFN treatment. Physicians should be aware of this late-onset complication.