Alcohol abuse and addiction during pregnancy can induce damage of the heart muscle and heart defects in the offspring. Between 1973 and 1991 216 children with fetal alcohol syndrome were diagnosed and examined for congenital heart defects. In 63 children (= 29,1%) heart defects were present, established mainly by heart catheterization and/or echocardiography. Most frequently ventricular septal defects (24/63) and atrial septal defects (23/63) occurred, less frequent were AV-defects (3), PDA (3), Fallots teralogy (5), and other malformations (5). Biopsy during heart surgery in 3 children revealed histological and electron microscopic changes of alcohol-cardiomyopathy. Heart defects are predominantly found in children with higher degree of severity concerning the clinical syndrome, less frequently in alcohol effects (4/38 = 11%). Alcohol in pregnancy, even in the course of so called social drinking, usual drinking and binge drinking has to be considered as an essential and preventable co-factor within the multifactorial etiology of congenital heart defects.