A survey was planned for establishing the point prevalence at birth of congenital heart disease and for assessing at the same time the efficacy of a screening for such anomalies. This model included: (1) exact determination of the population under survey; (2) approximately complete ascertainment of all persons in the population studied; (3) identical principles of cardiologic screening; (4) application of modern cardiologic diagnostic methods, and (5) a sample of over 2,000 persons. 23 cases of congenital heart diseases were found among 2,259 children born 1963 in a defined Hungarian territory. This means a point prevalence of 10.2 ± 2.1%₀ live births. (An additional 6 doubtful cases were not taken into account.) From the 12 cases diagnosed in vivo, 10 were detected by the screening.