The death is a major accident of which the assessment and analysis are needed to improve the quality of care in an ICU. The aim of our work was to study mortality, analyze the main causes and assess avoidable and non-avoidable causes, in order to target possible preventive action. Prospective study carried out in the surgical intensive care unit, including all patients who died more than 48 hours after admission. Several severity scores were tested (Apache, SOFA, IGS), but none of them showed superiority over the others, and therefore represent only estimates of the severity of multivisceral failure. This high mortality rate can be explained by several factors: age, causal pathology and associated defects, but also by nosocomial infections, which remain a major cause and which can be reversed by preventive measures, in particular the correct prescription of antibiotics.