Blood is a vital and life saving fluid which can neither be manufactured in factories, nor substituted with blood of any other creature. At the same time, blood proves to be a good medium for the growth of any organism because of its nutrients and oxygen, thus gets easily infected. The purpose of the study is to assess the knowledge among B. Sc Nursing I year students regarding blood donation before and after administering the planned teaching programme and to assess the effectiveness of planned teaching programme on knowledge among B. Sc Nursing I year students regarding blood donation. The study method was evaluative research approach and a pre experimental (one group pre test and post test) was used. Randomized sampling technique was used to select the sample. The total sample was 30 students. Pre test and post test knowledge score was assessed by self administered questionnaires. The result of the study concluded that mean and standard deviation of knowledge level score in pre test was 8.87, 1.48 and post test score were 18.47, 2.17. The calculated‘t’ value was 27.03 which is statistically significant in p value (0.001***). It reveals that there was a significant difference in pre test and post test knowledge score. It is evident that the planned teaching programme was significantly effective in improving knowledge regarding blood donation among B. Sc Nursing I year students.