Background: Thromboembolism is known as a major complication of nephrotic syndrome, but only 4 cases of portal vein thrombosis have been reported as a complication of nephrotic syndrome. All of these 4 cases had acute symptoms, and 3 of 4 were in relapsing phase of nephrotic syndrome when thrombi were found. We describe here a case of 51-year-old woman with fresh nephrotic syndrome that was asymptomatically complicated by portal, splenic and renal vein thrombosis. Conclusion: In the presence of fresh nephrotic syndrome of minimal change, asymptomatic and widely distributed, including portal vein, thrombus formation occurred. If the clinical course shows resistance to therapy, we must consider the complication of venous thrombosis. Anticoagulant therapy with heparin and warfarin was effective and all thrombi disappeared without any other complications.