The aim of the study was to analyze causes, location and signs and symptoms of the upper extremity deep vein thrombosis (UEDVP) in twelve patients who were referred for tests for trombophilia; these patients were treated from 2002 to 2009 in various Clinics of Warsaw Medical University.Material and methods. Retrospective analysis involved collection of clinical data of hospitalized patients related to signs and symptoms and location of the thrombosis, antithrombotic treatment and results of tests for thrombophilia. Patients with thrombosis caused by dialysis catheter, chemotherapy or paranteral nutrition and cardiac pacemaker electrode were excluded from the study.Results. Eight of the study subjects had a primary thrombosis: in as many as five of them this was an exercise-induced thrombosis. Secondary thrombosis was diagnosed in four patients, two of whom had a malignancy, the third one used oral contraceptives while the fourth, pregnant patient, had UEDVP associated with ovarian hyperstimulation syndrome.Conclusions. Pulmonary embolism (PE) without lower extremity thrombosis should prompt the search for UEDVT that can be asymptomatic. One of the study subjects underwent imaging studies that confirmed presence of thrombosis of the left brachiocephalic vein only after PE was detected.The study group contained many relatively young patients (five patients) with exercise-induced UEDVT, indicating possible thrombotic complications following too vigorous physical exercise.UEDVT that occurred in a pregnant patient was a complication of hormonal stimulation of ovaries used in the treatment of infertility. Pain and edema of the neck in such patients should prompt their attending physician to perform imaging studies. Should UEDVT be detected, antithrombotic heparin therapy should be started.