This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.Green discoloration of the urine after propofol administration is a rare clinical phenomenon. Although the exact incidence of propofol-induced green urine is not known, the reported incidence is thought to be less than 1%. In most reported cases of propofol-induced green urine, the clinical effects were benign and reversible. However, many clinicians are unfamiliar with this rare side effect of propofol. Here, we present the case of a patient who showed green urine following two-staged repair of a thoracoabdominal aortic aneurysm with propofol infusion. His urine had a normal yellowish color after the first operation, but appeared green immediately after the second surgery. Because propofol is a commonly used sedative agent, knowing that green urine can be attributed to propofol administration and that its clinical effect is mostly benign will help clinicians with patient management, as such knowledge will also reduce unnecessary concerns and laboratory tests. Propofol is a commonly used sedative agent for induction and maintenance of general anesthesia and for sedation in the intensive care unit (ICU). However, urine discoloration after propofol infusion and its clinical association is not widely known to clinicians because of its rare occurrence. Although the exact incidence of propofol-induced green urine is unknown, reported incidence is suggested to be less than 1%.There have been only a few previous reports of this green discoloration of urine after propofol administration [1][2][3][4][5][6][7][8][9][10][11]. We experienced a 27-year-old man who showed green urine after two-staged repair of a thoraco-abdominal aortic aneurysm. His urine color was normal yellowish color after the first infusion of propofol, but appeared green immediately after the second surgery with propofol administration. We report this case with a review of the relevant literature. the ICU and transferred to the general ward on postoperative day 2. During the time interval between the first and second operations, his systolic blood pressure and heart rate were controlled at 90 to 100 mmHg and around 90 bpm, respectively, with intermittent infusion of intravenous esmolol (50 g/kg/min) and/or nicardipine (1 g/kg/min). Intravenous famotidine, codein, and warfarin were also used occasionally. CASE REPORTHe was on oral carvedilol and losartan. During this time, the intraoperative and postoperative urine was normal yellowish.Seven days later, open repair of an abdominal aortic aneurysm was performed under the same TIVA technique. The intraoperative anesthetic and hemodynamic management was similar to that during the Bentall operation. Total anesthesia time was 4 hours and 42 minutes, with total propofol dosage of 2,100 mg. During this abdomin...