AbstractThe development of a retroperitoneal abscess in the setting of duodenal perforation is a rare occurrence. There are various causes of duodenal perforation such as trauma, iatrogenic injury and, most commonly, peptic ulcer disease [1]. Urgent surgical intervention is required when a patient presents with a perforated duodenal ulcer and signs of peritonitis. Generally, closure is performed with an omental pedicle or Graham patch [2]. In cases of large perforations, surgical resection, gastric partition with diverting gastrojejunostomy or T-drain placement may be required [2]. In this case, we present a patient with duodenal ulcer perforation complicated by retroperitoneal abscess formation. Treatment involved interventional radiological (IR) drainage of the abscess, followed by laparotomy for persistence of fluid. The surgery comprised of a right-side hemicolectomy, Braun jejunojejunostomy, pyloric exclusion, intraoperative retroperitoneal abscess drainage and Graham patch repair of retroperitoneal duodenal perforation.