At present thrombosis of the superior vena cava is an uncommon event that is now more frequently associated with diagnostic or therapeutic catheterization. If an apparent spontaneous thrombosis occurs, malignancy should be considered in the differential diagnosis. One case of clinically symptomatic thrombosis of the internal jugular, subclavian, and superior vena cava is presented. We detected an asymptomatic left renal cell carcinoma in a 54-year-old patient and nephrectomy was performed. Increased blood coagulability as part of a paraneoplastic syndrome was considered to be the possible etiology. In patients with otherwise unexplained superior vena cava thrombosis, examination not only of the head and neck but also of the abdomen, retroperitoneum, and pelvis should be pursued. A review of the literature pertinent to this rare case is provided.