BACKGROUND: Trocar site hernia (TSH) is a rare but potentially dangerous complication of laparoscopic surgery, and the drain-site TSH is an even rarer type. Due to the difficulty to diagnose at early stages, TSH often leads to a delay in surgical intervention and eventually results in life-threatening consequences. Herein, we report an unusual case of drain-site TSH, followed by a brief literature review. Finally, we provide a novel, simple, and practical method of prevention. CASE SUMMARY: A 54-year-old female patient underwent laparoscopic subtotal hysterectomy and bilateral adnexectomy for uterine fibroids 8 d ago in another hospital. She was admitted to our hospital with a 2-d history of intermittent abdominal pain, nausea, vomiting, and abdominal enlargement with an inability to pass stool and flatus. The emergency computed tomography scan revealed the small bowel herniated through a 10 mm trocar incision, which was used as a drainage port, with diffuse bowel distension and multiple air-fluid levels with gas in the small intestines. She was diagnosed with drain-site strangulated TSH. The emergency exploratory laparotomy confirmed the diagnosis. A herniorrhaphy followed by standard intestinal resection and anastomosis were performed. The patient recovered well after the operation and was discharged on postoperative day 8 and had no postoperative complications at her 2-wk follow-up visit. CONCLUSION: TSH must be kept in mind during the differential diagnosis of post-laparoscopic obstruction, especially after the removal of the drainage tube, to avoid the serious consequences caused by delayed diagnosis. Furthermore, all abdomen layers should be carefully closed under direct vision at the trocar port site, especially where the drainage tube was placed. Our simple and practical method of prevention may be a novel strategy worthy of clinical promotion.