Cancellation of surgical cases is increasingly considered as an adverse event that requires routine monitoring because of its effects on utilization of health system resources. The aim of this study was to determine prevalence and identify the reasons of cancellation of scheduled surgery Yazd ShohadaKargar hospital, Iran. This is a retrospectivestudy to descriptivereasons of surgery cancelation.Medical records were reviewed all patients scheduled for elective surgeries in a period of 1 year, starting from 21stof March 2011 to 20thof March2012. The reasons of surgery cancelation were divided as avoidable and unavoidable reasons. Statistical analysis was performed using SPSS version 20 software.A total of 14,670cases were scheduled to undergo elective surgical procedures. Of those, 274 cases were cancelled (1.87%). Majority 184 (67.2%) of cancelation was due to avoidable reasons other 90 (32.8%) due to unavoidable reasons. The highest number of cancelation caseswere occurred in the general surgical service 70 (25.5%) followed by orthopedic surgery 65 (24%) and Gynecology surgery 45 (16.5%). There were many causeswere recorded for cancellation of surgeries, the most common cause was cancellation due to patient medical problems (35.6%) and the second most common cause of cancellations was patient refusing the surgery (28.4%). The least cause of cancellations was due to problem with Facilities(4.4%). In conclusion, majority of the cancelation was due to avoidable reasons. The highest number of cancellation occurred in the general surgical, orthopedic surgery and Gynecology surgery.The most common causes for surgery cancelation were due to patient medical problems and patient refusing the surgery. The least cause was due to problem with Facilities.