AbstractPerforation peritonitis is associated with a severe morbidity and mortality. Patients outcome is significantly influenced by early adequate surgery and/or peritoneal drainage: moreover, even early and adequate empirical antimicrobial therapy influences patients morbidity and mortality. Surgical treatment usually consists of a laparotomy to eliminate the source of infection, peroperative peritoneal lavage to reduce the bacterial load, and prevention of persistent or recurrent infection. The open approach ie. Laparostomy, showed beneficial results as the percutaneous drainage of abscess from an open abdomen prevented penting up of infectious materials inside the abdomen and hence avoided further complications like burst abdomen, sepsis and death. Our study focuses on evaluation of scoring systems like APACHE II and MPI andcomparison of effectiveness of laparostomy vs primary closure in severe secondary peritonitis. 60 patients were randomly divided into two groups of 30 each. The two scoring systems were evaluated for their predictive power in terms of mortality; and the two surgical procedures in terms of outcome.