We compared the findings of noncontrast-enhanced CT with those of contrast-enhanced CT in 126 patients with blunt abdominal trauma to evaluate the usefulness of noncontrast-enhanced CT. In 112 of the patients, visceral injuries were confirmed by surgery or clinical follow-up including CT. Although noncontrast-enhanced CT diagnosed all patients with 12 intestinal injuries requiring immediate surgery, contrast-enhanced CT missed two of these patients because high density hematomas on noncontrast-enhanced CT became isodense after IV administration of contrast material. However, contrast-enhanced CT was superior to noncontrast-enhanced CT in the diagnosis of hepatic and renal injuries. A case of renal artery occlusion was only visualized on contrast-enhanced CT. We conclude that both noncontrast- and contrast-enhanced CT should be performed for the CT evaluation of blunt abdominal trauma.