Introduction: Peritonitis is an inflammatory or suppurative response of the peritoneal lining to direct irritation. Surgical treatment for perforation peritonitis is highly demanding and very complex. The combination of improved surgical technique, antimicrobial therapy, and intensive care support has improved the outcome of such case. A scoring system which can compare patient populations and severity of illness, objectively to evaluate the treatment strategy is the required for evaluative research of intensive care. The present study was undertaken to evaluate the efficacy of Mannheim Peritonitis Index (MPI) score in patients with perforation peritonitis.