Acute appendicitis is the most common condition requiring surgical intervention in childhood. The clinical diagnosis of acute appendicitis is often not straightforward and can be challenging. Approximately one-third of children with the condition have atypical clinical findings and are initially managed nonoperatively. There is currently great variability in the utilization of imaging for the assessment of suspected acute appendicitis in children. The principal imaging modalities utilized are graded-compression sonography and CT. Sonography has important diagnostic limitations that are addressed by CT. The principal advantages of CT include its operator independency, with resultant higher diagnostic accuracy, enhanced delineation of disease extent in perforated appendicitis, and improved patient outcomes including decreased negative laparotomy and perforation rates.