Despite more than four decades of investigation, the etiology of Kawasaki disease remains obscure, and none of the proposed etiologic theories for the disease have achieved independent confirmation. Clinical and epidemiologic features support an infectious cause, but the etiology remains unclear. The authors present a case of Kawasaki disease associated with Epstein-Barr virus and Mycoplasma pneumoniae infection in a 3.5-y-old boy. He received two doses of intravenous immunoglobulin due to prolonged course of Kawasaki disease but later had complicated autoimmune haemolytic anaemia. His prolonged fever subsided after azithromycin administration. Epstein-Barr virus infection was confirmed by molecular microbiological pathology of cervical lymph node and serological tests. The serological tests for Mycoplasma pneumoniae also revealed a positive result. Thus, it is concluded that Mycoplasma pneumoniae and Epstein-Barr virus infections may occur simultaneously in a child with Kawasaki disease. In addition, autoimmune hemolytic anaemia may be noted in Kawasaki disease patients after high-dose IVIG administration. To the authors' knowledge, this is the first report of Kawasaki disease with Epstein-Barr virus and Mycoplasma pneumoniae in the English-language literature.