An 8-year-3-month-old male with right porencephaly and epilepsy was found to have skin rash 2 weeks after the beginning of treatment with lamotrigine. One month later he suffered from impaired liver function and pancytopenia in the presence of hypocellular bone marrow with hemophagocytosis. No evidence of infection was evident. Intravenous immunoglobulin and steroid were administered with discontinuation of lamotrigine; the hemogram and liver function profile improved dramatically. Hemophagocytic syndrome should be considered a possible cause of pancytopenia in patients taking new antiepileptic drugs such as lamotrigine.