AIM: To establish whether infection with Epstein-Barr virus (EBV) contributed to the development of coronary artery lesions in a six year old child with an aneurysm and stenoses of the coronary arteries and suspected Kawasaki disease. METHODS: Postmortem paraffin wax sections of the coronary artery and myocardium were examined by in situ hybridisation for expression of EBER-1 (EBV-encoded RNA-1). Positive controls consisted of an EBV positive case of Hodgkin disease and a case of posttransplantation lymphoma. RESULTS: No EBER-1 positive cells were identified in either myocardium or walls of the coronary artery. CONCLUSIONS: Although EBV has been implicated in the aetiology of Kawasaki disease and development of coronary artery lesions, this process was not confirmed in this patient. It is likely that an unusual immunological reaction to a primary EBV infection with suspected deregulation of T helper cell activity leads to severe coronary artery damage in early childhood.