An understanding and knowledge of the path physiology of transfusion reactions, symptoms and treatment is essential to safely administer and monitor transfusion. Aim of the study: to evaluate the effectiveness of structured teaching program on knowledge and practice of nurses on blood transfusion. Material and methods: A quasi-experimental research design was utilized on a convenient sample of 30 nurses. The study was conducted in the general medical and hematological departments at TantaUniversityHospital. Three Tools used for data collection includetool I to assess sociodemographic nurses data and knowledge. Tool II Observation check list sheet:to assess nurse's practice. ToolIII Construction of teaching program.Results: 43.3 % and 93.3% and 66.7 % respectively of the total sample of nurses pre program ,immediately and after one month of post program had correct answer about blood and blood transfusion. There was progress in information immediately after the program and after one month from the program than before the program (76.7%, 66.3% , 26.7% ) respectively . The finding indicated that there was statistical significant difference and improvement of nurses' performance in immediately and after one month of the program from pre the program. Conclusion:there was a great improvement in the knowledge and practice score levels obtained by nurses after implementation of nursing intervention program immediately and after one month of follow up. Recommendation: Nurses are in need for in-service training programs and refreshing courses to improve their knowledge which will reflect on their practice.