Acute appendicitis is the most common cause of acute abdomen requiring emergency surgery. In particular, it affects patients older than 20 years and diagnosis is challenging in this patient subset. The radiologic methods (ultrasound and computed tomography) play a key role in the identification, characterization and staging of the disease as well as optimal timing of surgery. The aim of our study is to assess the usefulness of ultrasound imaging in the diagnosis of acute appendicitis and in a retrospective analysis of 54 ultrasound and computed tomography exams performed in the emergency department.