Upper extremity deep venous thrombosis is a serious disease entity which, based on the pathogenesis and in view of the individual patient's prognosis, must be divided into a primary and a secondary form. Primary upper extremity deep venous thrombosis is, when related to effort, a rather benign disease with excellent prognosis quoad vitam, carrying only a minor potential of developing disabling post-thrombotic syndrome. If primary upper extremity deep venous thrombosis occurs without any obvious cause, screening for underlying malignancy is recommended. Secondary upper extremity deep venous thrombosis typically occurs in older patients with severe comorbidities, mainly related to indwelling central venous catheters and cancer. As a consequence of the underlying diseases, prognosis of secondary upper extremity deep venous thrombosis is poor. Despite a lack of high-quality validation data, ultrasonography is regarded the first-line imaging technique, since it is a non-invasive method without exposure to radiation. In case of a non-diagnostic result of ultrasonography, other imaging modalities such as magnetic resonance imaging and computed tomography may be applied. Regardless of the etiology, the cornerstone of therapy is anticoagulant treatment with low molecular weight heparin or unfractionated heparin and vitamin K antagonists in order to prevent thrombus progression and pulmonary embolism. Owing to a lack of evidence, the optimal duration of anticoagulant treatment remains unclear. The additional benefit of compression therapy as well as of more aggressive therapeutic approaches such as thrombolysis, angioplasty and surgical decompression of the thoracic outlet needs to be investigated in randomized trials.