Every year, over 2500 unnecessary appendectomies are carried out in the Netherlands. At the initiative of the Dutch College of Surgeons, the evidence-based guideline on the diagnosis and treatment of acute appendicitis was developed. This guideline recommends that appendectomy should not be carried out without prior imaging. Ultrasonography is the recommended imaging technique in patients with suspected appendicitis. After negative or inconclusive ultrasonography, a CT scan can be carried out. Appendectomy is the standard treatment for acute appendicitis; this can be done either by open or laparoscopic surgery. The first choice treatment of appendicular infiltrate is conservative treatment.