BACKGROUND: Intestinal ischaemia as a result of small bowel obstruction (SBO) requires prompt recognition and early intervention. A clinicoradiological score was sought to predict the risk of ischaemia in patients with SBO. METHODS: A clinico-radiological protocol for the assessment of patients presenting with SBO was used. A logistic regression model was applied to identify determinant variables and construct a clinical score that would predict ischaemia requiring resection. RESULTS: Of 233 consecutive patients with SBO, 138 required laparotomy of whom 45 underwent intestinal resection. In multivariable analysis, six variables correlated with small bowel resection and were given one point each towards the clinical score: history of pain lasting 4 days or more, guarding, C-reactive protein level at least 75 mg/l, leucocyte count 10 x 10(9)/l or greater, free intraperitoneal fluid volume at least 500 ml on computed tomography (CT) and reduction of CT small bowel wall contrast enhancement. The risk of intestinal ischaemia was 6 per cent in patients with a score of 1 or less, whereas 21 of 29 patients with a score of 3 or more underwent small bowel resection. A positive score of 3 or more had a sensitivity of 67.7 per cent and specificity 90.8 per cent; the area under the receiver operating characteristic curve was 0.87 (95 per cent confidence interval 0.79 to 0.95). CONCLUSION: By combining clinical, laboratory and radiological parameters, the clinical score allowed early identification of strangulated SBO.