Background: High rates of cancellation of surgical procedures are common in hospital settings which may subsequently lead to economic loss to hospital besides burden given to patients, their families and medical teams .It is well recognized that cancellation of patients from elective theatre operating lists increases cost, decreases efficiency, duplicates workload and wastes operating room time.Cancellation of elective surgical procedures also causes significantly emotional trauma to the patients as well as their families and the community in general, and its impact on hospital resources is great due to prolonged hospitalization and high cost of health care.The aim of this study was to find the causes and incidence of surgical patient cancellation at Gondar university hospital, North-west Ethiopia.Methods: prospective observational study was conducted from January 10 to April 10, 2019. Information regarding the cancellation of surgeries were collected from various sources including; the operating room daily surgical schedule, preoperative anaesthesia record sheet, primary physicians, the anaesthetist responsible for the preoperative assessment and conducting the case and by communicating patients if required. Data were checked on daily basis for completeness and were entered to Epi info and analyzed using statistical package for social sciences (SPSS) version 20 software.Result: There were 64 causes of case cancellation. The commonest reasons for cancellation were overbooking of elective surgeries (33.13%).Conclusion: Preventable causes of case cancellation were the most prominent.