The objective of this study was to evaluate the changes that occurred in the treatment of migraine over a 10-year period in a pediatric emergency department (ED) after the implementation of a protocol. The method employed was a comparative retrospective chart review of children diagnosed with migraine in an ED. The two study periods were 1996-1997, and 2006-2007. A protocol suggesting a specific approach was implemented in the ED in 1999. The primary outcome was the medications used in the ED. There were 182 visits for migraine in 2006-2007 compared with 144 visits in 1996-1997. More patients were treated in the ED in 2006-2007 compared with 1996-1997: 50 versus 30%, a difference of 20% (95% confidence interval: 9, 30). The treatments used were also different. In conclusion, a variation in the treatment of migraine was observed over a 10-year period in a pediatric ED after the implementation of a treatment protocol.