Mesenteric vein thrombosis is a relatively rare cause of intestinal ischemia. We present a case of idiopathic superior mesenteric and portal vein thrombosis, which was not associated with any infarcted bowel. The patient was treated successfully with anticoagulation using low-molecular weight heparin and warfarin, and did not require bowel resection. This case highlights the value of diagnostic laparoscopy for assessing intestinal viability in this situation, showing how it avoids the morbidity and complications associated with a formal laparotomy.