Aim: Blood transfusion is also a tissue transplant and continues to be applied in many areas. Blood Transfusion training should be given to all healthcare professionals, and information should be updated in light of new developments. In our study, we aimed to evaluate the knowledge of physicians and nurses about the clinical use and transfusion of blood products. Material and Method: A questionnaire consisting of 16 questions was applied to 147 doctors and nurses working in the surgical and coronary intensive care units of XXXX Hospital between 01.10.2021 and 15.10.2021 to determine and compare their knowledge levels on blood and blood product transfusion. Questionnaire questions were prepared under four main headings: Basic transfusion information, clinical use of blood products, transfusion reactions, and storage of blood products. Results: 65.3% (n: 96) of the participants were female, and the mean age was 29.6±6.5. The mean age of the doctors and nurses, respectively (35.3±8.1 vs. 27.4±4.0 <0.001), was statistically significant. No employee could answer all questions correctly, and only four physicians answered 15 questions correctly. Nurses could answer a maximum of 13 questions (n: 3). While physicians gave statistically significant answers to 4 questions in total, it was determined that other healthcare professionals gave statistically better answers than physicians in only one question (Question 14). All employees’ average correct answers were 9 (range 7–10). Physicians gave correct answers to 10 (9–12) questions and other healthcare professionals 9 (7–10) questions, and it was not statistically significant. Conclusion: It is essential to maintain the knowledge level of physicians and health workers in transfusion practices after graduation. It should be ensured that they benefit from scientific meetings and in-service training regarding current developments.