Portal vein thrombosis (PVT) is a rare form of venous thrombosis that affects the hepatic portal vein flow, which can lead to portal hypertension. Treatment of PVT includes anticoagulants, thrombolysis, insertion of shunts, bypass surgery, and liver transplantation. Single anticoagulation therapy is not regarded as a curative treatment but can be associated with a reduction in new thrombotic episodes. We experienced a case of acute total occlusion of PVT provoked by protein C and S deficiency syndrome. PVT was completely recanalized with oral anticoagulant therapy following low molecular weight heparin therapy.