Introduction Elective surgical case cancellation is common and can have significant adverse rneffects and causes prolonged waiting times, harm to patients, and are a waste of scarce resourcesrnin countries like Ethiopia. Cancellation of scheduled surgery leads to operating theatre underoccupancyrnandrnisrnrecognizedrnasrnarnmajorrncausernofrnemotionalrntraumarntornpatientsrnandrntheirrnfamilies.rnrnReasonrnforrnelectivernsurgeryrncancellationrnisrncomplexrnandrndifferentrnfromrnhospitalrntornhospitalrnmanyrnrnliteraturesrnrnagree with patient related, facility related, medical related and staff related othersrndivide reason in to two avoidable and non-avoidable causes. rnObjectives: The aim of this study was to assess prevalence of cancelation of elective surgicalrnoperations and associated factors at public teaching hospitals of Addis Ababa, Ethiopia, 2021. rnMethod: This was institutional based cross-sectional study conducted in all operation theaterrnspecialties from February 1-March 30/2021 at TASH and Yekatite 12 hospital. The studyrnsubjects were all patients, of all ages and both genders who were scheduled for elective surgery.rnData were collected by using pretested structured questionnaires and an assigned OR staff wasrnrecording the cancelled cases in real time. Data was entered in to SPSS version 25 for analysisrnand the result of study was explained by narratives, tables and graphs rnResult: For the given study period, 924 elective surgeries were scheduled to be performed in allrnsurgery department at TASH and Yekatite 12 hospital, of which 225 (24.35%) were cancelled onrnthe day of surgery. The average age was 35.2 Â± 19.17(SD) years the main reason for cancellationrnwere shortage of time 26% followed by facility related 23%, medical related 18% and covid 19rnrelated problems 15%. rnConclusion and recommendation: This study found out that the cancelation of elective surgicalrnoperation on the scheduled day of surgery was very significant. Most of the reasons werernsupposed to be avoidable. A team approach ensuring presence of polices and procedure forrnimproving OR efficiency and scheduling realistic operation list.