Accurate diagnosis and treatment of small bowel obstruction (SBO) is critical to prevent complications and reduce costs. The purpose of the current study was to evaluate the evolving role of CT scan for patients with suspected SBO and compare its sensitivity and specificity with plain abdominal films. We identified 108 patients over a 1-year period with an admission or discharge diagnosis of SBO. Five patients treated on a clinical basis without radiographic imaging and those with indeterminate films were excluded from analysis. CT and radiograph reports were compared with operative findings or clinical course in 103 patients. By the clinical course, 66 of the patients had a partial or complete SBO. Plain film radiography correctly established the diagnosis of SBO in 50 of 66 patients (sensitivity, 75%). Nine of 17 plain films were true negatives (specificity, 53%). CT was able to correctly identify partial or complete SBO in 35 of 38 patients (sensitivity, 92%) and correctly identified the lack of obstruction in 8 of 13 patients (specificity, 71%). These data document that plain films are a less sensitive and less specific method of diagnosing SBO and confirm that the use of CT scan is a valuable modality. CT scan should be considered for use as the primary test for patients with suspected SBO.