Commercially available ultrasound equipment has been successful In early detection of congenital cardiac defects, facilitating prompt treatment of these often fatal anomalies.Congenital cardiac defects are not common, but their serious consequences make early detection and treatment essential. In developing a set of workable criteria for selective screening of serious abnormalities, the authors used commercially available ultrasound equipment in more than 500 high-risk pregnancies. Possible future applications include elucidation of causes of fetal cardiac defects.