Introduction: For patients with acute gangrenous appendicitis, it is common to provide antibiotics during 5-7 days in order to reduce the incidence of infection of the surgical wound; however the benefit of such treatment has not been tested. A prospective, randomized controlled clinical trial was conducted at the Hospital Universitario de Santander to test the effectiveness of providing a single 1-dose therapy of antibiotic prophylaxis versus a 5-day antibiotic therapy in patients with acute gangrenous appendicitis.