Once the criteria for red blood cell transfusion (indications, parameters, and guidelines) were reviewed in the literature, there was a need to evaluate and determine how these hemocomponents are prescribed in practice.A prospective descriptive cross-sectional observational study was conducted over a period of threemonths, which resulted in a sample of 397 transfusion events with the following outcomes: the average age was 60.9 years (SD 18.9 years); the most frequent bloodgroup was O (64 %) and Rh-positive (96 %); the average pre-transfusion hemoglobinwas 7.3 g/dL (SD 1.8 g/dL) and the average post-transfusion hemoglobin 9.4 g/dL (SD 1.7 g/dL); Internal Medicine was the service with the highest transfusion prescriptions (29.5 %); 34 % of transfused patients were hospitalized in floors (general ward); 64.5 % of the requests were for 2 units of red blood cells; 63.4 % of indications were nontraumatic, traumatic, and surgical hemorrhage and in 71 % of therequests the indication was not clearly recorded in the medical history; and during the observation period, only one post-transfusion adverse event was reported.The study results evidenced the need to undertake educational measures as well as socialization events of clinical practice guidelines in relation to the use of blood components, an activity that is expected to have a favorable impact in terms of adverse events and rational use of resources.