Behçet's disease is a chronic multisystem vasculitis of unknown aetiology. This case report describes a patient who applied to the hospital because of dyspnoea, ascites, oedema of lower extremities and recurrent episodes of haemoptysis. For the last 12 yr, he had superior vena cava syndrome (SVCS) and cardiac and pulmonary involvement of Behçet's disease, and biochemical examination of ascite fluid yielded a chylous effusion containing triglyceride 421 mg dl-1 and cholesterol 49 mg dl-1. Chyloptysis was also detected by Sudan III stain. The patient died from cardiac tamponade in spite of cardiac fenestration. To the authors' knowledge, this is the first reported case of Behçet's disease with chylous ascites and chyloptysis in the English literature.