BackgroundBlood can save millions of lives. Even though people do not donate blood regularly, there is a constant effort to balance the supply and demand of blood. The aim of this study was, therefore, to determine the knowledge, attitude and practice of blood donation between university students.MethodsThe comparative cross sectional study design was used in Adama Science and Technology University and Arsi University from April 11–May 2, 2016.360 students were selected using stratified sampling. Frequencies and proportions were computed. Chi-Square and logistic regressions were carried out and associations were considered significant at p<0.05.ResultThe study revealed that there was a significant knowledge difference (χ2 = 152.779, p<0.001) and Attitude difference (χ2 = 4.142, p = 0.042) between Health Science students of Arsi University and Non-Health Science students of Adama Science and Technology University. The gender of the students (AOR = 3.150, 95% CI: 1.313, 7.554) was a significant predictor of the level of knowledge of Health Science students. The ethnicity of students (AOR = 2.085, 95% CI: 1.025, 4.243) was a significant predictor of the level of an attitude of Health Science students and gender of students (AOR = 0.343, 95% CI: 0.151, 0.779) was a significant predictor of the level of an attitude of Health Science students. Concerning Non-Health Science students, religion (AOR = 10.173, 95% CI: 1.191, 86.905) and original residence (AOR = 0.289, 95% CI: 0.094, 0.891) were a significant predictor of the level of knowledge of Non-Health Science students. Gender (AOR = 0.389, 95% CI: 0.152, 0.992) and Year of study (AOR = 0.389(0.164, 0.922) were significant predictor of level of attitude of Non-Health Science students. Year of study (AOR = 5.159, 95% CI: 1.611, 16.525) was a significant predictor of level of practice of Health Science students.ConclusionSignificant knowledge difference and attitude difference were observed between students from Arsi University and Adama Science and Technology University.