OBJECTIVE Prognosis of hospitalized patients depends on the status of nutrition, the intensity of the biologic inflammatory response or acute phase response (APR), triggered by cytokine, and the illness severity. These factors have been shown closely related, as cytokine causes malnutrition and organ failure. AIM to analyze which of these factors are related to mortality and, by multivariate analysis, which of them have an independent predictive value. METHOD We include 119 patients admitted to a semi-intensive care unit. Nutritional assessment was performed by mid arm anthropometrics, serum albumin, transferrin, IGF-I, and subjective nutritional evaluation; we also determine acute phase proteins and cytokine IL-1, TNF alpha and IL-6. Severity of illness was assessed by organ failure. The only end point considered was death or survival until discharge of hospital. RESULTS The following data were related to increased mortality: impaired alimentary habits and nutritional subjective assessment, raised serum levels of IL-6 and neutrophil differential count, decreased lymphocyte count, hemoglobin and serum transferrin levels, a negative PPD and the presence of sepsis, shock or organ failure. At multivariate analysis (stepwise logistic regression) only nutritional variables, sepsis and organ failure data showed an independent predictive value, whereas IL-6 was displaced by organ failure data. CONCLUSION Regarding prognosis, severity of illness and nutritional status have independent predictive value, whereas IL-6 was displaced, probably because it is closely related to the inflammatory response and to organ failure.