Colonoscopy is commonly performed for diagnostic and therapeutic purposes and has a relatively low morbidity rate. Nevertheless, it is necessary for operators to be aware of the rare complications of colonoscopy due to a large number of procedures performed in daily practice. Acute appendicitis is an unusually rare occurrence after colonoscopy, with no clear association being found between the colonoscopy and acute appendicitis. A rapid diagnosis of this complication is possible by widespread awareness in surgeons regarding this condition. Acute appendicitis cannot be reliably resulted in as the cause of acute abdominal pain due to relatively subtle signs, symptoms, and studies performed for bowel perforation. The diagnosis of postcolonoscopy appendicitis is difficult, and strategies for its treatment show significant variation. This report presents a patient having undergone urgent laparotomy within 12 h after colonoscopy on having signs and symptoms of acute appendicitis-induced peritonitis.