Fetal echocardiography has become, in the last few years, an essential tool in the perinatal care of the fetus at risk for congenital heart disease. From January 1989 to October 1996, 2265 fetal echocardiograms were performed. The main reasons for referral were: gestational diabetes in 852 patients (39.4%), fetal arrhythmias (338 patients - 15.6%), previous diabetes mellitus (223 patients 10.3%), history of congenital heart disease in the offspring (203 - 15.6%) and abnormal routine obstetric ultrasound examination (201 - 8.9%). Of the 2265 studies performed, 523 (23.1%) showed cardiac abnormalities. Arrhythmias were the most common findings (194 cases). Premature atrial and ventricular beats were the most common abnormalities of cardiac rhythm (120 cases) followed by complete AV block (14 cases), supraventricular tachycardia (13 cases) and atrial flutter (7 cases). There were 123 cases of hypertrophic cardiomyopathy, 119 in fetuses of diabetic mothers. Among the patients with structural congenital heart disease, the abnormalities most frequently encountered were VSD (70 patients), complete AV septum defect (18 patients), DORV (14 patients), pulmonary atresia (9 patients), Ebstein's anomaly (8 patients) and TGA (6 patients). The highest yield of abnormal results occurred among patients referred for arrhythmias (50%). Seventy six fetuses were admitted to the Fetal Cardiac Unit for monitoring and management. Seventy invasive procedures were performed: 30 cordocentesis, 22 amniocentesis, 10 blood transfusions, 2 pleural drainages, 1 pericardial drainage, and 1 balloon aortic valve dilatation in a fetus with severe aortic stenosis, and four other minor procedures. Prenatal detection allows for optimization of perinatal care and, when indicated, early intervention. The efforts of a multidisciplinar team may represent a better prognosis for the fetus with congenital heart disease.