OBJECTIVE: To examine the influence of massive perioperative transfusion on both short-term and long-term outcomes in children undergoing brain tumor resection. METHODS: This retrospective cohort study analyzed pediatric patients who underwent brain tumor surgeries at the Women and Children's Medical Center, Guangzhou Medical University, between October 2014 and March 2022. Massive transfusion was characterized as the transfusion of red blood cells equivalent to or exceeding the estimated preoperative blood volume within 48 h after surgery. To evaluate the relationship between massive transfusion and patient outcomes, logistic regression models were utilized. Survival curves were constructed to compare the long-term outcomes of patients who received massive transfusion with those who did not. The primary outcomes assessed were 30-day all-cause mortality (short-term outcomes) and 1-year survival rates (short-term outcomes). RESULTS: Among the 306 patients included in the analysis, 78 were categorized as part of the massive transfusion group, while 228 were in the non-massive transfusion group. Multivariable regression analysis indicated that perioperative massive transfusion was significantly linked to an increased risk of 30-day mortality (odds ratio (OR): 0.137, 95% confidence interval (CI) [0.036-0.528], CONCLUSIONS: Massive transfusion has a pronounced impact on short-term outcomes, particularly increasing perioperative mortality and complication risks in children undergoing brain tumor surgery. Careful consideration of the risks and benefits of transfusion is crucial in managing these cases.