A retrospective study of cases and controls was carried out, based on the review of medical records, obtaining a sample of 240 postoperative patients with severe intra-abdominal sepsis (120 cases and 120 controls) in the Intensive Care Unit of the Regional Teaching Hospital of Trujillo during the period 2006-2012; with the aim of demonstrating whether the age, anatomical origin of the infection, comorbidity, APACHE II scale, ASA scale, serum lactate level in the first 24 hours, ventilatory support, inotropic support and number of surgical interventions are risk factors associated with mortality. The frequency of severe intra-abdominal sepsis was 31.3% and the mortality found was 60.4%. The variables that constituted risk factors associated with mortality were: age> = 65 years (OR = 3.1 and p = 0.004), APACHE scale> = 15 points (OR = 2.5 and p = 0.009), ASA scale> II (OR = 3 and p = 0.005...