Abstract Background The rate of recurrent appendicitis is low following nonoperative management of complicated appendicitis. However, recent data suggest an increased rate of neoplasms in these cases. Methods The study was a retrospective review of patients with acute appendicitis at 2 university-affiliated community hospitals over a 12-year period. The primary outcome measure was the incidence of appendiceal neoplasm following interval appendectomy. Results Six thousand thirty-eight patients presented with acute appendicitis. Appendectomy was performed in 5,851 (97%) patients at the index admission. Of the 188 patients treated with initial nonoperative management, 89 (47%) underwent interval appendectomy. Appendiceal neoplasms were identified in 11 of the 89 (12%) patients. These included mucinous neoplasms (n = 6), carcinoid tumors (n = 4), and adenocarcinoma (n = 1). The rate of neoplasm in patients over age 40 was 16%. Conclusions There is a significant rate of neoplasms identified in patient over age 40 undergoing interval appendectomy. This should be considered following nonoperative management of complicated appendicitis.