Advances in cardiac surgery now enable many children with congenital heart disease (CHD) to survive to adulthood. The influence of such advances on the frequency of various lesions among adult patients undergoing cardiac catheterization (CC) has not previously been addressed. This retrospective analysis of 329 adults with CHD undergoing CC at an adult and at a pediatric referral center demonstrates that when compared to 20 years ago, adults with CHD who now undergo CC are more likely to have complex cardiac disease, and more have had prior surgery. In addition, despite more aggressive surgical management, ventricular dysfunction and dysrhythmias are now commonly encountered residua of CHD in adults who require diagnostic CC. Premature coronary artery disease appears uncommon. These changing characteristics of adults with CHD require consideration in the planning of future health care for these patients.