Selective downward gaze paralysis has not previously been described as a complication after posterior fossa operations in children. The authors found downgaze palsy to be a transient complication after resection of large pediatric posterior fossa midline tumors reaching the aqueduct of Sylvius. They reviewed the cases of 2 children with large posterior fossa midline tumors who underwent resection via an inferior transventricular approach. They developed a hypothetical scheme to account for downward gaze paralysis based on anatomy and insight gained from experimental studies. The authors describe potential risk factors for developing transient selective downward gaze paralysis with the hope of making more pediatric neurosurgeons aware of this complication following removal of lesions around the mesencephalic periaqueductal gray matter. Recognition and understanding of downward gaze palsy after posterior fossa surgery should improve preoperative counseling and promote postoperative family coping.