Background: Acute appendicitis is the most common cause of the acute abdomen requiring surgery with a lifetime risk of 6%-8%, which is maximal in childhood and declines steadily with age as the lymphoid tissue and vascularity atrophy. The aim of the present study was to Compare between Open and laparoscopic appendectomy in complicated cases as regard post-operative improvement (Pain, leakage, sepsis, hospital stay, return to work). This study was a Prospective non randomized study which included100 patients (50 open technique , 50 laparoscopic technique ) from emergency department at Benha University Hospital and. Through one year started from 1st of may 2020 to 30th of april 2021.