Appendicitis is the most common surgical emergency in childhood and the technologic advances of modern medicine have affected the diagnosis and treatment of appendicitis. This study is to evaluate the differences in diagnosis and treatment of appendicitis between present and 10 year ago. The authors retrospectively reviewed the medical records of patients who underwent appendectomy under the diagnosis of the acute appendicitis from July 1993 to June 1995 (Group A, n = 78) and from July 200 to June 2005 (Group B, n = 105). There are no differences between group A and B in mean age (8.5 ±3.6 vs. 9.3 ±3.1 year), duration of symptoms (3.0 ±3.2 vs. 2.6 ±3.8 days), and postoperative hospital stay(6.6 ±4.8 vs. 5.8 ±3.6 days). Preoperative abdominal ultrasonogram and/or computed tomogram was performed in 7 patients (9.0 %) of group A and in 51 patients (58.5 %) of group B. Thirty-six patients (34.3 %) of group B underwent laparoscopic appendectomy, but none in group A. Incidence of a histologically normal appendix decreased from 15.8 % in group A to 4.8 % in group B (p =0.018). This study suggests that utilization of abdominal ultrasonogram or computed tomogram in preoperative evaluation become more popular and surgical treatment of acute appendicitis become more minimally invasive. The rate of negative appendectomy was also reduced compared with 10 year ago.