Behçet's disease involving the heart is extremely rare. Sometimes it is probable to misdiagnose as infective endocarditis when protracted fever and chill occurs. We report a case of protracted pyrexia of unknown origin after surgical excision of a cardiac tumour. Clinically and pathologically a diagnosis of infective endocarditis was probable but antibiotics had no effect. After case review the diagnosis of Behçet's disease was established and the patient was treated with glucocorticoids which resulted in resolution.