Upper extremity venous thrombosis is a clinical entity with numerous etiologic factors. Only 2% of all cases of deep venous thrombosis involve the upper extremity, and the incidence of pulmonary embolism related to thrombosis in this location is approximately 12%. Primary or "effort" thrombosis of the upper limb is related to the inherent anatomical structure of the thoracic outlet and axillary region. Secondary thrombosis may have such diverse origins as trauma, infection, congestive heart failure, central venous catheters, neoplasms, septic phlebitis, intravenous drug use, and hypercoagulable states. Patients present with peripheral edema and prominent superficial veins, and neurologic symptoms (pain and paresthesias) are usually present as well. Clinical diagnosis is confirmed by venography or sonography. Treatment regimens include conservative measures, thrombolysis with fibrinolytic agents, and surgical correction of indicated thoracic outlet and axillary structures. We present an unusual case in which upper extremity venous thrombosis in a young healthy female athlete was associated with the presence of cervical ribs. The patient was successfully treated with focal thrombolysis and surgical resection of her ipsilateral cervical rib.