The incidence of congenital heart disease (CHD) in the Western industrialized world has varied from a low value of about 3 to 5 per 1000 live births to about 12 per 1000 live births. Most of the lower incidence figures were obtained before there were sufficiently well trained pediatric cardiologists and before the success of cardiac surgery put a premium on early and correct diagnosis of CHD. The advent of echocardiography with Doppler color flow measurements has made it possible to diagnose lesions that are asymptomatic, minor, and even without murmurs. Given these differences, there does not appear to have been a significant increase in the incidence of CHD over the last 20-30 years. The incidence of CHD in underdeveloped countries is not known, but the distribution of different lesions is fairly similar to those in developed countries except perhaps for fewer with aortic stenosis and coarctation of the aorta.