Background:.This red liquid caries oxygen and nutrients to all the parts of body and carries carbon dioxide and other waste products back to the lungs, kidneys and liver for disposal. It fights against infection and helps to heal wounds, so that we can stay healthy. There is no substitute for blood. If people lose blood from surgery or injury or if their bodies can’t produce enough, there is only one place to turn –‘Voluntary blood donors.Objective of the study:– 1)Assess the existing knowledge toward   blood donation among undergraduate students.2) Assess the attitude   toward   blood donation among undergraduate students. 3) Assess the effectiveness of planned teaching program on knowledge and attitude toward    blood donation among undergraduate students.4) Associate knowledge toward blood donation among undergraduate students with selected demographic variables.5) Associate the attitude toward blood donation among undergraduate students with selected demographic variables. Material and Method: Quasi Experimental research design – one group Pre test and post testdesign Population was 200 undergraduate student studying in selected arts commerce, and science colleges. Structured questionnaireand attitude scale were used to collect the data.The content validity of the tool was done by various experts from different fields.Result. post test 2(1%) of undergraduate students were having average level of knowledge score, 16.5% had good and 82.55% of them had excellent level of knowledge score. The minimum score in posttest was 10 and the maximum score was 20, the mean score for the posttest was 14.85±2.38 and percentage score was 89.25±11.93. post test 1(0.5%) of undergraduate students were disagreed,2% were undecided, 45.5% were agreed and 52% were strongly agreed about  attitude score. The minimum score in posttest was 18 and the maximum score was 50, the mean score for the posttest was 41.89±6.84  and percentage score was 83.78±13.68Conclusion: The pre test findings showed that knowledge and attitude toward blood donation among undergraduate students was inadequate. The administration of planned teaching program helped the undergraduate students to understand toward blood donation.