Objectives: We aimed to investigate the clinical features of upper extremity deep vein thrombosis (UEDVT). Methods: We retrospectively reviewed the background, thrombus site, treatment, and outcome of 76 UEDVT patients. Results: Of the 76 UEDVT patients, 44 (57.9%) were men, and 51 (67.1%) were complicated by malignancy, 44 (57.9%) had an indwelling central vein (CV) catheter, 8 (10.5%) had concomitant pulmonary embolization (PE), and 33 (43.3%) were symptomatic. Regarding the thrombus site, the right internal jugular vein was the most common, with 30 cases (35.3%). As regards the treatment method, 53 patients (69.7%) received oral anticoagulants. In 2015, when direct oral anticoagulants (DOACs) was covered by insurance, there were 44 UEDVT cases, of which 34 (77.3%) received DOACs. Outcomes at a mean observation period of 37.5±41.5 months included 40 deaths (52.6%) with a mean survival of 16.3±21.3 months. The most common cause of death was malignancy, with 33 cases (82.5%). Conclusion: In the background of UEDVT, the combination of indwelling CV catheter placement and malignancy was frequently observed. While the risk of recurrence or PE complications is low, the prognosis of UEDVT complicated by malignancy is extremely poor.