To aimed to determine the incidence of complications of endoscopic sinus surgery (ESS) and to investigate the factors associated with the occurrence of complications.In this retrospective study, we reviewed the medical records of all patients who had undergone ESS at King Saud University Medical City (KSUMC) between January 2015 and March 2022. Patients who underwent ESS for complicated acute sinusitis, sinonasal malignancy, and cerebrospinal fluid leak repair, and those who underwent extended ESS for indications other than chronic rhinosinusitis were excluded. This study was approved by the KSUMC Institutional Review Board.We included 1395 patients, 3 of whom had major complications and 28 had minor complications, resulting in an overall major complication rate of 0.2% and a minor complication rate of 2%. The most common major complication was orbital hematoma, and the most common minor complication was synechia. Moreover, the duration of surgery and laterality increased the risk of complications, whereas the use of image guidance had no effect.The ESS is a safe procedure. The operative start time and laterality were associated with an increased risk of complications and warrant further investigation.