Background: Childhood immune thrombocytopenia is a common bleeding disorder that resolves spontaneously in 70–75% of cases. The main cause is viral infection, which typically responds to intravenous immunoglobulin (IVIG) or steroid treatment. Cytomegalovirus (CMV) causes severe infection in prematurely born infants or immunocompromised hosts. However, the clinical manifestation of CMV-associated thrombocytopenia in healthy children after neonatal period is unclear. Methods: The medical records of thrombocytopenia children after neonatal period at three university hospitals in Daegu from January 2000 to March 2017 were retrospectively reviewed. Results: There were 1,065 children enrolled in this study; 33 (3.1%) were confirmed as CMV-associated thrombocytopenia and eight showed positive polymerase chain reaction ( PCR) result for CMV with negative IgM. The median age at diagnosis was 13.8 months and the median platelet count was 24,000/µL. Five subjects were diagnosed with Evans syndrome, 15 showed hepatic dysfunction, two had pneumonitis, and one had gastritis. IVIG was used for 25 patients, and six patients showed recurrence. IVIG was re-used or antiviral agent was added. Steroid was used in four patients, and it did not raise the platelet count in one patient. The antiviral agent was used for nine CMV-associated thrombocytopenia subjects. Conclusion: Although many cases of CMV-associated thrombocytopenia are resolved by IVIG, about 30% of patients need further therapy, including antiviral agent for disease control.