Appendicitis is a common childhood condition requiring surgical intervention and delayed diagnosis can have serious consequences. This report describes the case of a child who presented with an acute abdomen and intestinal obstruction. Multidetector (MD) CT demonstrated a left-sided caecum and an inflamed appendix with a faecolith. Maximum intensity projection (MIP) post-processing was key in identifying the appendicular artery and determine the diagnosis. At surgery, however, a mobile caecum and the appendix were positioned on the right side.