Brain tumors presenting in infancy, especially during the first 6 months of life, are often very large and highly vascular. It is generally accepted that gross total resection of the tumor affords the best outcome to the patient. However, tumor resection is frequently very challenging due to the risk of significant bleeding. We report two cases of congenital glioblastoma whose initial surgery was hampered by tumor hypervascularity and excessive blood loss, resulting in subtotal resection. Subsequent carboplatin-based chemotherapy led to a significant reduction in tumor size and vascularity, enabling safe gross total resection at second-look surgery. Based on these findings and a review of the literature, we recommend cytoreductive chemotherapy following diagnostic biopsy for infants presenting with large, highly vascular tumors, such as congenital glioblastoma, in lieu of aggressive upfront surgery, to increase the feasibility and facilitate safe gross total excision at second-look surgery.