Two patients, a 25-year-old male and a 57-year-old female, were treated for stump appendicitis. Both patients had undergone appendicectomy 6 months previously and again presented with pain in the right lower abdominal region. On physical examination, the first patient had tenderness as well as rebound tenderness over the entire abdomen, indicative of a general peritonitis. The second patient had tenderness and rebound tenderness in the right iliac fossa alone. Both patients underwent a laparotomy. In the first patient a perforated appendiceal stump was found and removed. In the second patient an acutely inflamed appendiceal stump was found and removed. Appendicitis of a residual appendiceal stump following incomplete appendicectomy is a rare cause of abdominal pain. A lack of familiarity with this condition frequently causes a delay in diagnosis, which increases the chance of perforation and intra-abdominal sepsis. Therefore, all clinicians need to be aware of the possibility of stump appendicitis and to take appropriate measures to prevent serious complications should they suspect this.