Abstract: OBJECTIVE:To investigate the clinical application of percutaneous endoscopic gastro/jejunostomy (PEG/J) in critically ill patients. METHODS: The clinical data of 45 critically ill patients with PEG/J were retrospectively analyzed, and the surgical indications, operation points, perioperative management, surgery-related complications and clinical outcomes were summarized. RESULTS: PEG/J was successful in 44 critically ill patients, with an average operation time of (7.5±2.3) min for PEG and (10.3±8.5) min for PEJ, and an average retention time of (168±121) d for PEG/J. No intraoperative placement-related complications or serious postoperative complications occurred. Intraoperative heart rate and oxygen saturation decreased significantly in one case, which improved after symptomatic treatment. Postoperatively, one patient developed local soft tissue infection, one case developed J-tube dislodgement into the body, one case developed encapsulation syndrome, and two cases developed jejunal nutrient tube blockage. Compared with the preoperative period, the serum albumin and prealbumin levels of the patients tended to increase at the 4th postoperative week, but the difference was not significant. Conclusion Performing PEG/J in critically ill patients is an effective method for establishing long-term gastrointestinal nutrition access, which is minimally invasive, safe, with few complications and easy to care for, and is well tolerated by patients and can be left in the nutrition tube for a long time.