Thrombophilia is a state of hypercoagulability defined by biological abnormalities predisposing to thrombotic events. The aim of this study was to evaluate the demands of thrombophilia assessment and its biological profile during thrombotic events in young subjects. This is a retrospective study including 969 patients with venous thromboembolic disease and 211 cases with arterial thrombosis. PS and CP determination by chronometric method, TA determination by chromogenic method, detection of CPPa and CCA type LA by chronometric method, and detection of Factor V Leiden polymorphism by specific PCR-allele were performed. In venous thrombosis, hereditary thrombophilia was found in 208 cases with 184 isolated anomalies and 24 combined anomalies. LA-type ACC was found in 50 patients and mixed thrombophilia was noted in 14 cases. In arterial thrombosis, hereditary thrombophilia was found in 35 cases with 31 isolated anomalies and 4 combined anomalies. Our study reveals the importance of clinical information and complete and controlled investigations.