Background. Though World Health Organization recommends 100% voluntary blood donation, the percentage of blood collected from voluntary blood donors and the average annual blood collection rate are extremely low in Ethiopia. The role of adults is crucial to meet the demand of safe blood. Thus, this study aimed to assess knowledge, attitude, and practice of adult population towards blood donation in Gondar town, Northwest Ethiopia. Method. A community based cross-sectional study was conducted among 768 adults. Multistage sampling technique together with simple random and systematic random sampling technique was employed. Bivariate and multivariate logistic regression analysis and bivariate correlation analysis were done. Result. About 436 (56.8%), 630 (82%), and 141 (18.4%) study participants had adequate knowledge, good attitude, and experience of blood donation, respectively. Secondary and higher educational statuses were significantly associated with adequate knowledge towards blood donation. Participants who were protestant by religion were more likely to have good attitude towards blood donation. Age, self-perceived health status, and religion were significantly associated with blood donation practice. Conclusion. Knowledge and attitude towards blood donation are high. However, the level of practice is low. District and national blood banks and transfusion agency should design strategies that promote and motivate the communities to donate blood.