Blood transfusion was a revolution in Medicine, however, the reactions transfusions permeates it. This study aimed to evaluate and characterize the practice of pretransfusion medication and perception of physicians and nurses regarding this approach. Data concerning premedication were collected from physical and electronic medical records of onco-hematologic patients throughout the year 2021. Semistructured interviews were conducted to assess the knowledge of prescribing physicians and nursing staff. During this period, there were 688 transfusion events in the Oncologyhematology Unit, with premedication being used in 522 cases (75.87 %), most frequently for platelet concentrates. The most commonly used classes of medications were antihistamines (52.3 %) followed by analgesics (28.7 %). The majority of physicians reported prescribing premedication in cases of previous transfusion reactions. The most frequently hemocomponent prescribed (80 %) was random platelet concentrates. Concerning specific medications, 60 % mentioned diphenhydramine and 40 % mentioned dipyrone. Regarding nursing staff, 50 % stated that premedication was employed in 70-80 % of transfusions; 70 % reported that antiallergics were the most commonly prescribed, consistent with physician responses. Only 40 % mentioned seeking alternative measures to premedication, such as bedside observation, and 90 % expressed reluctance to administer blood components without premedication. Our findings reveal a widespread practice of premedication, reflecting a conservative approach that is increasingly being questioned and challenged. The high rates of premedication underscore need for reformulation and adoption of protocols that encompass best medical practices and continuous pursuit of preventive strategies, including alternatives to premedication and even transfusion itself, emphasizing restrictive transfusion practices through proper patient management.