We set out to determine the incidence of iatrogenic coronary artery dissection extending into the aorta and to characterize the aortic lesions. We reviewed the data from 43,143 cardiac catheterizations from September 1993 through September 1999 and found 9 coronary artery-aortic dissections for an overall incidence of 0.02%. Four of these patients were undergoing treatment for acute myocardial infarction (AMI) and aortic dissection was more common than for non-AMI patients (0.19% vs. 0.01%, P < 0.0006). Histologic analysis of tissue samples from 2 cases revealed age related changes only and no evidence of predisposing pathology. Patients with limited aortic involvement were successfully managed with stenting of the coronary dissection entry point whereas aortic dissection extending up the aorta >40 mm from the coronary os required surgical intervention.