Background: Computed tomography (CT) is currently the exam of choice for bowel obstruction. The test reports the etiology, site and grade of obstruction, and the presence of bowel ischemia, affecting the surgical decision. We undertook this study to determine the diagnostic accuracy of CT for bowel ischemia and the probability of surgery depending on signs of bowel ischemia and grade of bowel obstruction observed in CT in patients with adhesive small bowel obstruction. Methods: We carried out a retrospective study including patients from 2007-2010 admitted due to adhesive bowel obstruction and with intravenous contrast-enhanced abdominopelvic CT at admission. Tomographic signs of bowel ischemia were established and diagnostic accuracy was calculated. We also determined the probability of surgery depending on tomographic grade of obstruction and signs of bowel ischemia by subgroup analysis. Results: This was a cohort of 164 patients with a mean age of 60.4 ± 20 years; 87% had previous abdominal surgery and 86 patients required surgery (52%). In regard to tomographic signs of bowel ischemia, sensitivity was 72.5%, specificity 97.5%, positive predictive value 90%, negative predictive value 91%, positive likelihood ratio 29.9, and negative likelihood ratio 0.28. Tomographic signs of bowel ischemia simultaneously with high-grade obstruction presented an 83% probability of surgery; high-grade obstruction alone presented a 57% probability and in absence of both signs was 36%. Conclusions: There is good diagnostic accuracy for tomographic signs of bowel ischemia and its definitive presence. Tomographic signs of bowel ischemia simultaneously with high-grade bowel obstruction significantly increase the probability of surgery.