A 42 year old man admitted with effusive-constrictive pericarditis had diastolic dysfunction and pericardial thickening. Pericardiectomy was performed because of uncontrolled heart failure. The Epstein-Barr viral IgG antibody titre was exceptionally high. The EB viral genome was demonstrated in the resected pericardium by polymerase chain reaction and in situ hybridisation. EB viral pericarditis was diagnosed.