At more than 50%, appendicitis is the leading cause of acute intra-abdominal disease requiring surgery. In the course of various other operations, prophylactic appendectomy (PA) is frequently performed. This study examines to what extent PA is justified. A prospective study was performed in all patients (n = 173) undergoing prophylactic appendectomy in Katharinen Hospital Unna between January 2010 and October 2013. The following variables were analysed: age, gender, type of primary surgery, emergency or elective surgery, complications, lethality, intraoperative and histopathological evaluation of the appendix. In addition, patients were contacted postoperatively with the request to complete a questionnaire. Prophylactic appendectomy was carried out without any specific complications. 117 patients (68%) participated in the survey. 15% of these patients had suffered symptoms that could be attributable to irritation of the appendix. With only one exception, all appendectomy specimens revealed pathological findings in the histopathological examination. PA allowed the early diagnosis of 4 adenomas, one neuroendocrine tumour and 6 metastases or manifestations of peritoneal carcinomatosis. PA is ethically justifiable, as there are few complications. Moreover, it can help to avoid future appendicitis and allows early detection of malignancies.