There is no consensus guidelines for treating duodenal variceal bleeding, which is a rare and life-threatening complication of portal hypertension. Here we report an exceedingly unusual case in a 9-year-old boy who had developed left-sided portal hypertension after surgical treatment for pancreatoblastoma followed by a duodenal variceal bleeding with massive melena, severe anemia (hemoglobin 4.5 g/dL) and hypovolemic shock. Emergency partial splenic arterial embolization (PSE) provided a reduction of variceal bleeding and improved blood pressure. Endoscopic injection sclerotherapy (EIS) was subsequently performed and stopped the duodenal variceal bleeding without the complication of portal vein thrombosis caused by injected sclerosant under hepatopetal flow. Our case demonstrates that emergency combined therapy with PSE and EIS can be considered as the therapeutic option for the management of left-sided portal hypertension-induced ectopic variceal bleedings in order to avoid the complication of portal embolization by EIS and provide effective hematostasis.