Background Perforated gastroduodenal ulcer is commonly suspected clinically, and computed tomography (CT) is often performed before surgery. CT may identify the ulcer site, enabling a targeted surgical approach. Gut wall discontinuity (GWD) is a direct radiological sign that may allow identification. However, surgeon-led detection and utilisation of this sign for ulcer localisation has not been evaluated. Aim To assess the utility of GWD in surgeon-led CT analysis, specifically the accuracy and frequency of GWD. Methods A single-centre retrospective study was performed. Patients were adults with confirmed perforated gastroduodenal ulcers who underwent preoperative CT. CT reports were categorised as visible ulcer, suspicious, or non-suspicious. Ulcer location was confirmed from intraoperative reports or separate contrast study. A consultant surgeon, blinded to operative and radiology findings, reviewed CT images for GWD, recording predicted location and confidence (nil, some, moderate, very). Results 55 adults were included (median age 56). Confirmed sites were: 37 duodenal and 18 gastric (14 antral/pyloric, four other). Routine CT identified visible ulcer in 8/55(15%), suspicious in 39(71%), and non-specific in 8(15%). Surgeon-led review detected GWD in 32/55(58%). Accuracy for localisation was highest for duodenal (D1 87%, D2 100%) and lower for gastric (43%). Accuracy strongly correlated with confidence: low 0%, moderate 55%, high confidence 94%. Conclusion Surgeon-led CT review deliberately seeking GWD improves confirmation of perforated GUD ulcers. Importantly, high confidence in ulcer location was highly accurate, suggesting this sign is reliable. This study is limited by the single-surgeon status and its retrospective nature.