Background- Blood is a specialized body fluid in humans that delivers necessary substancesrnsuch as nutrients and oxygen to the cells and transports metabolic waste products away fromrnthem. Secure supply of safe blood components, based on voluntary, non-remunerated bloodrndonation, is an important national goal to prevent blood shortages.rnNow a day, in many low- and middle-income countries, blood supply is critically inadequate.rnSub-Saharan Africa, which has the highest maternal mortality rate in the world of 510 deathsrnper 100 000 live births, also has the lowest blood donation rates.rnThe donated blood plays a big role during surgery, accident, delivery cases, bleeding cases suchrnas peptic ulcer, liver diseases, lung diseases, cancer cases, blood diseases such as hemophilia,rnanemia and thalassemia, new born baby with blood diseases, burn cases etcrnObjective â€“ The objective of this study is to assess knowledge, attitude and practice of bloodrndonation among health workers in Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia.rnMethods- Institution based cross sectional study design was conducted among all health carernworkers of Tikur Anbessa specialized hospital. The dependent variable of the study werernknowledge, Attitude and practice where as the independent variables include health carernworkers socio demographic characteristics. The data was collected by pre-tested and structuredrnself administered questionnaire. Data quality was maintained by providing training to datarncollectors and by doing pre-test as well as by providing frequent supervision. Finally data wasrnanalyzed by using SPSS version 20 software.rnResult - All 295 respondents were in the age range of 21-59 years with a mean age of 28.23 &rnSD of 6.432 year. From the total participants 176(59.7%) were male. One hundred sixty (54.2%rn%) and 135(45.8%) of respondents have good and poor level of knowledge regarding bloodrndonation respectively. From the sociodemographic factors, sex was statistically and significantlyrnassociated with knowledge of blood donation. Being male was 1.75 times more knowledgeablernthan females [AOR (95%CI) 1.75(1.00, 3.07)]. The other statistically significant factor wasrnmarital status. Married health care workers were 3 times knowledgeable than single [AORrn(95%CI) 3.24(1.65, 6.37)].Department was also among the statistically significant factors. BeingrnLaboratory were 63% less likely to have good knowledge than physician [AOR (95%CI)rn0.37(0.12, 1.16). One hundred ninety five (66.1%) of respondents have poor attitude towardsrnblood donation. From the health care workers socio-demographic factors, age was statisticallyrnand significantly associated with attitude towards blood donation. Health workers agedrnbetween 31&40 were 1.5 times having good attitude towards blood donation than those whornare above 40[AOR (95%CI) 1.50(0.38, 5.89)]. Similarly, those health workers who had 6 monthrnto one year work experience 4 times having good attitude than those who had above 5 yearsrnexperience[AOR (95%CI) 4.08 (1.31,12.73)]. The other statistically significant socio-demographicrnfactor was department. Being a nurse were 51%less likely to have good attitude towards bloodrndonation than others (AOR (95%) 0.49 (0.23, 1.08)].rnKey words- Attitude, Blood donation, Donors, Health workers, Knowledge, practice