Congenital heart disease as a complicating factor in pregnancy has assumed increasing clinical importance because improved techniques of surgical repair have resulted in a larger proportion of affected women living to the reproductive age. The most serious forms are those associated with pulmonary hypertension (such as the Eisenmenger syndrome), which carry a prohibitively high risk of maternal death. Complex forms of cyanotic heart disease, of which the commonest is the tetralogy of Fallot, are only slightly less dangerous. It has recently been recognized that children born to women with congenital heart disease are at increased risk of having cardiac defects; fetal echocardiography is therefore an important diagnostic test. Optimal care of the pregnant woman with congenital heart disease is best provided by a team consisting of internist-cardiologist, obstetrician-perinatologist, obstetric anesthesiologist, and ultrasonographer-echocardiographer.