Eleven patients presenting with the clinical diagnosis of suspected aortic dissection underwent intravenous digital subtraction aortography. In nine patients digital subtraction angiography (DSA) was performed as the investigation of first choice. In five of these the diagnosis was confirmed with this technique alone and surgical repair was undertaken without further investigation. Direct cine aortography was also undertaken in the other four patients and confirmed the DSA findings, demonstrating aortic dissection in one case and no dissection in three others. In two of the eleven patients, direct cine aortography was performed as the initial investigation. The results of subsequent digital aortography concurred in both cases, aortic dissection being demonstrated in one patient. In two cases, despite normal cine and digital aortography, aortic dissection was confirmed by computed tomography. We have found DSA to be a valuable technique for diagnosing aortic dissection, with no false positive or false negative findings when compared to direct cine aortography. Since it is a less traumatic procedure than direct aortography it should be the investigation of choice if computed tomography is not immediately available.