Thrombophilia is characterised by elevated thrombotic and embolic risk and may be caused by congenital or acquired coagulating inhibitor deficit. A young man was repeatedly admitted to Emergency Medicine Units because of pain, oedema and slight functional impairment of the left leg, and recurrent thrombophlebitis was diagnosed. During the most recent hospitalization, vena cava thrombosis was diagnosed and therapeutic management consisted of application of a caval filter and administration of dicoumarin anticoagulants. This case can be classified as a hereditary protein S deficiency with APC-resistance. However, non-strenuous, protracted and repeated physical trauma may have acted synergically with the congenital coagulation inhibitor deficiency, determining the thrombotic episodes, which are probably provoked by transient and functional alterations of the non-thrombogenic properties of the endothelium.