PURPOSE: Carcinoids are rare neuroendocrine tumors, mainly detected in the gastrointestinal tract. This study was performed to evaluate the incidence and necessity for additional treatment in incidental appendiceal carcinoids from patients presenting with symptoms of acute appendicitis. METHODS: Of the patients; who underwent appendicectomies, with the diagnostic impression of acute appendicitis, from 1994 to 2003, six cases were diagnosed as appendiceal carcinoids. The medical records of these patients were retrospectively reviewed. RESULTS: During the study period, a total of 2477 patients (male: 1336 and female: 1141) underwent appendicectomies due to the diagnostic impressions of acute appendicitis, with 2 male and 4 female cases diagnosed as appendiceal carcinoids by pathological examination. The rate of incidental appendiceal carcinoids in those patients was 0.24% (male: 0.15% and female: 0.35%) An appendiceal carcinoid was detected in one of 396 child patients (0.25%), but in none of 610 patients over the age of 40. Additional bowel resections were necessary in two patients (33%) in whom the carcinoids had infiltrated the serosa or mesoappendix, and were involved in the resection margins In one of these (50%), the carcinoid had metastasized to regional lymph nodes. CONCLUSION: Incidental appendiceal carcinoids are not common events in patients with symptom of acute appendicitis. However, the possibility of a metastatic disease in these incidental carcinoids warrants careful considerations for additional treatment on the basis of a close pathological examination.