The purpose of the study is to demonstrate that antibiotic therapy is as safe and effective as appendectomy for the treatment of acute non complicated appendicitis. Two hundred fifty patients will be included in a prospective multicentric randomized trial. The primary endpoint is the rate of intra abdominal infections in both therapeutic strategies. Other criteria will be studied including duration of hospital stay and absence from work during a follow up period of one year, parietal and abdominal complications and recurrent appendicitis after antibiotic therapy.