Aneurysms of the portal vein and its branches have been rarely described. Their natural history is unknown although large ones (>3 cm in diameter) have been reported to cause rupture, thrombosis, duodenal or biliary obstruction, inferior vena cava compression and/or portal hypertension. We report the case of an incidentally diagnosed 4.5 cm splenic vein aneurysm repaired by endovascular treatment through a transhepatic route. The aneurysm was successfully excluded using a covered stent (Viabahn, Gore). The transhepatic route opens the possibility of offering a minimally invasive approach to vascular lesions of the portal vein system. Splenic vein aneurysms were first reported in 1953 (1) and they are part of the extrahepatic portal vein aneurysm group (2). Their mechanism of development is not well understood. Etiology may include congenital causes (inherent weakness of the vessel wall) or acquired causes (trauma, inflammation such as pancreatitis, liver disease, or portal hypertension). However, portal aneurysms do not seem to be the result of an isolated portal hypertension since they are extremely rare even in patients with this condition (3). The demographic characteristics of extrahepatic portal vein aneurysm include a female-to-male ratio of 2:1 and the median age of 52 years (range, 5–77 years). The size of the reported aneurysms ranges from 1.9 to 8 cm. The most common location of the aneurysm is in the main portal vein trunk, the junction of the superior mesenteric vein and the splenic vein, or at the hepatic hilus; intrahepatic venous aneurysms are rare (4, 5). Here, for the first time, we report the successful endovascular treatment of a splenic vein aneurysm through transhepatic percutaneous approach using a Viabahn stent.