Balloon-occluded retrograde transvenous obliteration (B-RTO) has been used successfully to treat gastric varices in adults. However, only a few case reports of B-RTO in children have been published. We describe a child who had gastric varices with extrahepatic portal venous obstruction (EHO). A 12-year-old boy presented to the pediatric clinic with anemia and tarry stools. He was referred to our department to receive additional treatment for gastric varices. Endoscopy revealed spurting bleeding from gastric varices, and emergent endoscopic injection sclerotherapy was performed. Angiography showed cavernous transformation of the portal vein, hepatofugal flow of the left gastric vein, gastric varices, and gastrorenal shunt. The gastric varices were not eradicated adequately with endoscopic sclerotherapy because of excessive regurgitant blood flow against the portal venous pressure. B-RTO combined with partial splenic embolization (PSE) was therefore performed. The gastric varices were completely eradicated with no complications. This is, to our knowledge, the first report describing the use of B-RTO combined with PSE in a child with EHO who had gastric fundal varices. B-RTO combined with PSE is not excessively invasive and is effective and safe for children. This procedure is therefore recommended for the treatment of gastric varices in children.