Superior mesenteric vein thrombosis (SMVT) is an uncommon but important clinical entity that can induce ischemia or infarction of the small and large bowel. It is rare and accounts for 5-15% of mesenteric vascular occlusions. Bowel infarction due to SMVT can present as an acute abdominal disease, requiring urgent laparotomy with resection of the intestinal segment affected. However, the clinical diagnosis of this event remains difficult and invariably requires specific imaging investigations in order to be able to treat the condition as soon as possible. SMVT without bowel infarction can present as persistent, non-specific abdominal pain and nausea with minimal clinical signs, affecting young individuals without any known predisposing disorder, where laparotomy is not an urgent indication. We report a case of a young adult man with SMVT due to a hypercoagulable state (protein S deficiency), in whom an early diagnosis and appropriate anticoagulant treatment prevented any further extension of the thrombotic process and limited the hemorrhagic infarction of the ileum, which simply required a segmental resection.