Although the cause of macrocephaly is found to be benign in many cases, the large differential diagnosis includes conditions that can be life-threatening. Prompt recognition and timely diagnosis can lead to a better prognosis in many cases. This issue summarizes the available literature on macrocephaly and provides recommendations for the evaluation, diagnosis, and appropriate disposition of children with macrocephaly in the acute setting. Developmental milestones, "red flags," and neurologic examination by age are reviewed to help narrow the differential diagnosis and identify underlying etiologies. Guidance is provided for which imaging studies are indicated, and recommendations are given for which children need transfer or admission.