Introduction: Cancellation of elective surgical operations is common, and most of these cancellations are due to preventable causes. Cancellation of operations increases cost and decreases efficiency. It wastes time and resources and causes emotional distress to the patients and their families. Aims and Objectives: The aims of this study were to investigate and analyze the reasons of cancellation of surgical operations, establish its extent, and suggest solutions. A prospective observational, hospital-based study conducted at Khartoum Bahri Teaching Hospital during a period of 1 year. Methodology: The study subjects included all patients, of all ages, both genders, scheduled for surgery from all surgical subspecialties except emergency, trauma operations, ophthalmology, obstetrics/gynecology, and cardiothoracic operations. Results: A total of 3990 patients were scheduled for surgery during 48 weeks. A total of 3185 operations were performed (79.8%), and 805 (20.2%) operations were canceled or postponed on the day of operation. The overall patients' related causes of cancellations accounted for more than 2/3 (68.28%). The major reason of cancellation of elective surgical operations (35.5%) was patients not attending to the surgery. Chronic medical diseases accounted for 21.97%. Lack of time was the reason of cancellation in 9.93%. Cancellation causes related to administration were 9.4%. Conclusion: Clinics for preoperative evaluation, timely communication, and prompt reminding of patients are effective measures for reducing the cancellation rate. Late cancellations of elective surgery will always be present due to intercurrent diseases, work commitment, and social obligations of the health care providers and patients