This podcast is part 3 of a 4-part series discussing an approach to abnormalities in head shape and size. This third part reviews the differential diagnosis for children presenting with large heads(macrocephaly). Key points on history and physical exam and the relevant investigations and management options for children with macrocephaly will be discussed. The podcast was created by Dr. Lindsey Logan, a pediatric neurology resident in Toronto, and Dr. Claire McNiven, a pediatrics resident at the University of Alberta. The podcast’s development and editing were supported by Dr. Melanie Lewis, a pediatrician at the Stollery Children’s Hospital, Dr. Lauren Redgate, a pediatrician in Calgary, and Dr. Peter Gill, a pediatrician at SickKids.