Abstract: ob＜x＞ject: To report the diagnosis and treatment of a patient with portal mesenteric vein thrombosis (PMVT) after laparoscopic sleeve gastrectomy. PMVT is rare and can be life-threatening if it occurs. Previously, there was only one case of PMVT after LSG reported in China 1. So we report this case occurred in our center to share the diagnosis and treatment experience.Method: The patient was a 51-year-old female with preoperative height of 162cm, weight of 98kg and BMI of 37.3kg/m2. She was admitted to hospital because of "me＜x＞tabolic syndrome, sleep apnea, et al.". The patient underwent LSG on May 24th 2021, and her severe cirrhosis was found during the operation. She was discharged successfully on May 26th 2021, and no abnormality was found in lower limb vascular ultrasonography. On the 14th day after surgery, the patient complained of abdominal pain. On the 19th day after surgery, the patient came to emergency due to unbearable abdominal pain. Multiple thrombosis in portal vein and superior mesenteric vein was diagnosed by abdominal CTA. Portal mesenteric vein catheterization through superior mesenteric artery and anticoagulant therapy were performed.Result: After treatment for one week , the upper abdominal CT showed that low density shadow was basically absorbed in portal vein. Then the patient was discharged successfully and continued oral rivaroxaban treatment. We followed the patient for 4 months after surgery, and she had no abdominal pain, with normal defecation, and she was satisfied with weight loss. We advised her to continue taking oral medication to prevent the recurrence of thrombosis and related complications.Conclusion: With the rising number of bariatric me＜x＞tabolic surgeries, the treatment of postoperative complications is particularly important. When patients have severe postoperative abdominal pain with sight signs, we should be alert to the occurrence of abdominal vascular thrombosis and even PMVT. Early detection and treatment of PMVT generally have a better prognosis and could avoid serious consequences.