PURPOSE: Epstein-Barr virus (EBV) is associated with various diseases and complications caused by the host's immune reactions. This study focuses on various clinical findings and hematologic complications in childhood EBV infection. METHODS: The study group was thirty-eight EBV infected children (Anti-EBV VCA IgM; positive) who were admitted to the Department of Pediatrics, Korea University from January 1996 to July 1997. Patients were evaluated by clinical and laboratory findings. RESULTS: The mean age was 5.1 years old and the male-female ratio was 1.2:1. Fever was the most common clinical manifestation, which was present in 30 (79%) cases. Lymphadenopathy was present in 22 (58%) cases, throat injection in 18 (47%) cases, nausea and vomiting were in 13 (34%) cases, cough in 13 (34%) cases, skin rashes in 11 (29%) cases, hepatomegaly in 10 (26%) cases. AST and/or ALT levels were elevated in 18 (45%) cases and Bilirubin level was elevated in 9 (24%) cases. Twenty cases had hematologic complications. Neutropenia was present in 6 (16%) cases, thrombocytopenia in 1 (3%) case, both anemia and neutropenia in 3 (8%) cases, both anemia and thrombocytopenia in 2 (5%) cases, both neutropenia and thrombocytopenia in 1 (3%) case, pancytopenia in 7 (18%) cases. CONCLUSION: A presumptive diagnosis of EBV infection may be made by the presence of clinical symptoms such as fever, pharyngitis, lymphadenopathy, and hematologic complications such as unknown neutropenia, anemia, thrombocytopenia, and pancytopenia. In such conditions, specific serologic studies for EBV should be performed and confirmed by specific serologic studies.