It is estimated that 30-50% of patients suffering from deep vein thrombosis (DVT) could be diagnosed with congenital or acquired thrombophilia. Its diagnosis, however, rarely changes the clinical management, but is associated with significant costs and negative psychological and social aspects. The aim of this study was to perform a retrospective analysis of the causes and clinical consequences of diagnostics for thrombophilia. A retrospective review of the medical records of 5600 patients was performed, 62 of whom had, at the time, been diagnosed for thrombophilia because of a thromboembolic event. A review of the current literature on the validity of diagnostic tests for hypercoagulability in certain clinical conditions was also performed. The most common reason for thrombophilia testing was episodes of lower limb DVT (56%). The most frequently diagnosed abnormalities were the heterozygous form of the V Leiden gene (18%), protein S deficiency (11%), and the anti cardiolipin antibody IgG (11%). In 45% of the patients, laboratory results did not confirm the presence of any congenital thrombophilia. After receiving the results, 11% of the respondents completed oral anticoagulation therapy after 3 months, and 28% of patients qualified for indefinite use of oral anticoagulant therapy. In most of the cases examined, the diagnosis of thrombophilia did not significantly affect the treatment. A common aberration identified in patients with a history of thromboembolic incidents was the coexistence of risk factors for atherosclerosis.