^{The aim of prospective study was to analyze prevalence, spectrum and effectiveness of antenatal cardiac nation-wide screening program of congenital heart disease (CHD) in a region with unselected population between 1986 and 2007. Prenatal echocardiographic examinations were performed in 10027 fetuses between 13 to 41 weeks of gestation (median 23 weeks). CHD was found in 1828 fetuses (545 had additional extra cardiac anomalies). Early termination was performed in 1040 (56.9%) cases, 60 (7.6%) died in utero, and 728 (92.4%) were born alive. Detection rate increased from 0.6% for all CHD and 2.3% for critical lesions in 1986, to 30.7% for all and 83% for critical CHD in 2007. The highest detection was in double outlet right ventricle (74%), hypoplastic left heart (51.2%), Ebstein anomaly (51.0%) and atrioventricular septal defect (43.2%). The lowest detection rate was in ventricular septal defects (2.6%) and pulmonary stenosis (3.2%). Antenatal detection rate increased significantly comparing two periods, 1987-1999 and 2000-2007. In the second decade of screening program, hypoplastic left heart was diagnosed prenatally in 95.2%, transposition of great arteries in 26.2%, and coarctation of aorta in 20.3%. In double outlet right ventricle, prenatal detection rate exceeded estimated postnatal prevalence. Conclusion: The nation-wide prenatal ultrasound program has enabled detection of cardiac abnormalities in 30% of patients born with CHD and more than 80% of those with critical forms. Prenatal ultrasound spectrum of CHD differed from that seen postnatally with high association of non-cardiac lesions. Supported by grants – NR9451-3/2007 and MZO 00064203}