There is a lack of evidence about the efficacy and safety of primary prophylaxis for bleeding in children with gastric varices, which contributes to the ongoing dispute around this topic. Here, researchers share details on their work using primary endoscopic prophylaxis. Primary prophylaxis (banding, n = 114; sclerotherapy, n = 31, predominantly in younger children) was performed on 145 children (median age, 3.5 years; cirrhosis, n = 116) with high-risk gastric varices between 2006 and 2019. After a mean of 6 months, they saw 93% of children with varices completely resolved, 45% with at least 1 recurrence of varices, and 17% with gastrointestinal bleeding. Grade 3 esophageal varices, the presence of gastric varices along the cardia, and a lower composite score of endoscopic severity were all associated with a lower probability of eradication, a longer time to eradication, a lower risk of a first recurrence, and bleeding after the procedure, regardless of the cause of portal hypertension. Overall survival at 10 years was 95% likely, and bleeding-free survival at 75% likely. In children at high risk for gastric varices, primary endoscopic prevention of variceal bleeding is efficacious and safe. Children with more advanced endoscopic characteristics have poorer outcomes. This emphasizes the importance of endoscopic screening for children with portal hypertension to identify varices early enough for primary prevention.