Portal-mesenteric venous thrombosis (PMVT) is a rare yet life-threatening complication following laparoscopic sleeve gastrectomy. Risk factors include obesity, metabolic disorders, intraoperative manipulation, and postoperative complications. However, its non-specific symptoms often lead to missed diagnosis. This article reports a case of PMVT after laparoscopic sleeve gastrectomy that was successfully treated with superior mesenteric artery catheter-directed thrombolysis combined with low-molecular-weight heparin anticoagulation. The purpose of this report is to enhance awareness among bariatric and metabolic surgeons regarding PMVT, emphasizing the importance of timely diagnosis and intervention to prevent severe consequences caused by delayed treatment.