Klinefelter's syndrome is the most common congenital abnormality that causes primary hypogonadism. It is associated with diseases that predominantly affect women, such as systemic lupus erythematosus (SLE), and it can sometimes cause veno-occlusive disease. We experienced a case of Budd-Chiari syndrome (BCS) in a 33-year-old man with Klinefelter's syndrome presented with hematemesis and edema in both lower extremities. The clinical and laboratory findings were compatible with SLE, antiphospholipid syndrome, and BCS. To the best of our knowledge, this is the first case report to describe a simultaneous presentation of these four clinical syndromes in a single patient.