Abstract : Endoscopic endonasal approach (EEA) has shown excellent results for most pituitary tumors. The purpose of this study is to evaluate and report the complications of EEA in patients with pituitary adenoma (PA) undergoing surgery between 2013 and 2021. A retrospective review of 152 consecutive patients with PA treated with EEA from May 2013 to January 2021/152 procedures was performed. Complications included electrolyte abnormalities, transient diabetic insipidus (DI) or new anterior pituitary hormone insufficiency on one axis, and major complications including CSF leak, hemorrhage and vascular injury, brain infection, new permanent panhypopituitary dysfunction (DI), new visual deficits, neurological deficits, and death ithin The first 48 hours after surgery and within the later 48 hours after surgery. Ninety-seven complications were seen in 152 patients (63.8%). The most common early complication at 48 hours postoperatively was hypokalemia (60.8%), treated with saline and potassium chloride; the second most common early complication was nausea and vomiting (40.2%), treated with antiemetic drugs, followed by diabetes insipidus (31.9%), treated according to blood sugar levels. After 48 hours, the most common late complication was cerebrospinal fluid leak (6.2%), which was treated surgically; the second most common late complication was vision loss (5.2%), which was treated conservatively. EEA can be considered a safe surgical treatment with acceptable complications and low mortality in PA management, and complications should be managed in a timely and appropriate manner.