A case of Paget-von Schrötter syndrome diagnosed with gadolinium-enhanced magnetic resonance (MR) venography is described. MR enabled a comprehensive evaluation with identification of the thrombus within the left subclavian vein and a hypertrophied anterior scalene muscle as the probable cause of the patient's condition. We describe the MR venography technique used for evaluation of the subclavian vein and the imaging findings in this entity.