In Ethiopia, medical waste management has become a problem due to an ever-increasingrnnumber of hospitals, clinics, diagnostic laboratories and other health care services.rnAlthough health care workers are one key personnel for the proper management of medicalrnwastes at any health facilities, their level of performance depends on their level ofrnknowledge, practice and some related factors regarding medical waste management. ArnQuantitative institutional based cross sectional study and a qualitative observational studyrnwas conducted and a total of 627 health care workers from 4 public hospitals at AddisrnAbaba, Ethiopia, were included. Study participants were allocated proportionally based onrnthe number of healthcare workers from each hospital and profession. Data were collectedrnusing pre-tested self-administered structured questionnaires and observational checklists.rnThe collected data was analyzed using SPSS version25.0. Multivariable logistic regressionrnmodel was used to identify factors associated with knowledge and practice of healthcarernworkers. Out of the total respondents, 52.7% and 51.5% of health care workers hadrnadequate knowledge and adequate practice towards medical waste management,rnrespectively. Hospital working hours of 8 per day [AOR=1.5, 95% CI (1.09, 2.18)],rnGetting MWM information from guidelines [AOR=1.54, 95% CI (1.087, 2.189)] andrnadequate practice score [AOR = 2.14, 95% CI (1.50, 3.02)] were significantly associatedrnwith the knowledge level of health care workers. On the other hand, HCWs working atrnSaint peter hospital [AOR=4.1, 95%CI (2.78-7.75)], professional categories,rnDoctors[(AOR=3.8,95%CI(1.2-12.70],Nurse[(AOR=4.4(1.38-13.8)]MTs [(AOR=9,rn95%CI(2.3-44.9)], getting medical waste management information from trainingrn[AOR=2.1,95%CI(1.58-3.50), getting medical waste management information fromrnothers[(AOR=0.49,95%CI(0.25,0.95)], presence of MWM guidelines inrnhospital[(AOR=1.73, 95%CI(1.04,2.88)] and adequate knowledge scorern[(AOR=2.10,95%CI(1.45-3.048)] were significantly associated with practice level ofrnhealth care workers. In this study, both knowledge and practice level of health care workersrntowards medical waste management were not satisfactory. To improve better, proper and intensive job training is recommended.