Hemodialysis-associated subclavian venous stenosis should be suspected when upper extremity edema occurs after a graft or fistula has been placed there. Alternatively, venous thoracic outlet syndrome could also produce venous congestion, simulating subclavian stenosis. The latter diagnosis was unsuspected until central subclavian vein obstruction on venography became complete, with the arm passively hyperabducted. The patient’s symptoms resolved after surgical decompression. Causes of thoracic outlet obstruction are reviewed.