Obstructions of the superior vena cava whether partial or complete are rare clinical, surgical and pathological entities. Thrombosis resulting from injury, usually of an indirect nature to the superior vena cava, is probably the etiological agent. The clinical manifestations which alarm the patient are a gradually developing edema of the upper half of the body especially the face, the tortuous, distended veins of the chest and neck, and cyanosis of the lips and lobes of the ears. The symptoms will be modified or exaggerated depending upon the location of the lesion in relation to the vena azygos which may in certain instances partially take over the function of the superior vena cava. The prognosis depends upon the rapidity in the formation of adequate collateral circulation and surgical eradication of the obstructing mass. Obstruction Above the Orifice of the Vena Azygos, Case 1: This man of 45 years, a mechanic, entered the hospital complaining of swelling of face and eyelids, lacrimation and distended veins of neck, chest and abdomen. Twelve months previous to admission he developed bilateral swelling of the neck believed to be due to adenitis. He was treated and in two or three weeks the face began to swell and the veins of the chest became distended. He was able to walk or run without difficulty but his work or excitement seemed to aggravate the condition. His family and regional history were non contributory. Physical examination revealed a well developed male in no acute distress. The face was flushed, swollen but no pitting edema was present. His chest was symmetrical, respiratory excursion equal, 20/mm., and the percussion notes and tactile fremitus were equal. No rales were detected. The cutaneous vessels were dilated and tortuous, especially in the neck, and radiating medially from the axilla. There was a tortuous tender vein to the right of the sternal border. The superficial epigastrics were markedly distended but not tender. The heart rate, 80 per minute, was of good quality. No detectable enlargement or murmurs were present. Blood pressure was 122,72 left arm, 120/68 right arm and 120/80 right leg. The abdomen, skin, extremities, neurological findings, ear, nose and throat were within normal limits. X-ray film inspection of the chest was normal. Urine with specific gravity of 1.004, and acid, contained no sugar, al