BACKGROUND The anemia is a common problem upon admission of the patients in the intensive care unit being the red blood cell transfusion a frequent therapeutic. The causes of anemia in critical patients who under go red blood cell transfusion are several: acute loss of blood after trauma, gastrointestinal hemorrhage, surgery amongst others. Currently, few studies are available regarding the use of blood components in patients at intensive care unit. Although blood transfusions are frequent in intensive care unit, the optimized criteria for handling are not clearly defined, with no available guidelines. OBJECTIVE To analyze the clinical indications of the use of the red blood cell in the intensive care unit. METHODS The clinical history of the patients admitted in the intensive care unit were analyzed, revisiting which had have red blood cell transfusion in the period between January 1st 2005 and December 31 2005. The study was accepted by the Research Ethics Committee - Comitê de Ética em Pesquisa (CEP) - of the University of South of Santa Catarina (UNISUL). RESULTS The transfusion rate was 19,33, and the majority of the patients were of the male gender. Their age prevalence was of 60 years old or older. The mortality rate among patients who under went red blood cell transfusion died was of 38,22%. The transfusions criterias were low serum hemoglobin (78%) and the hemoglobin pre - transfusion was 8,11 g/dL. CONCLUSIONS Politrauma and sepsis/sepsis chock were the pre diagnosis criteria. A low hemoglobin level is the main clinical criteria with average hemoglobin pre - transfusion was 8,11 g/dL.