OBJECTIVE: To determine whether delaying appendectomy for 12 hours to avoid disturbing the operating room schedule and to minimize the number of operations during the night negatively affects the outcome of patients with acute appendicitis. DESIGN: Retrospective study. SETTING: Large teaching community hospital. PATIENTS: The medical records of 380 patients who underwent appendectomies between January 1, 2002, and December 31, 2004, were reviewed. Patients proven to have an inflamed appendix on the pathological report were divided into 2 groups. The early group comprised patients who had undergone appendectomies within 12 hours of presentation to the emergency department, including patients with generalized sepsis. The late group comprised patients who had undergone appendectomies more than 12 to 24 hours after presentation. MAIN OUTCOME MEASURES: Length of stay, operative time, and the rate of perforations and complications. INTERVENTIONS: Laparoscopic or open appendectomies. RESULTS: There were 309 patients included in our study. There were no statistically significant differences between the early and late groups in the length of stay, operative time, the percentage of advanced appendicitis, or the rate of complications. CONCLUSIONS: In selected patients, delaying appendectomies for acute appendicitis for 12 to 24 hours after presentation does not significantly increase the rate of perforations, operative time, or length of stay. It decreases the use of the nursing staff, anesthesia team, and surgical house staff during the night shifts, and it decreases the interruption of the regular operating room schedule.