Angiotensin-converting enzyme (ACE) inhibitors are widely used for controlling hypertension. Their use in women who are pregnant is not without risk to the fetus. We describe three infants exposed in utero to ACE inhibitors who had adverse outcomes. These cases, combined with other reports in the literature, suggest strongly that these drugs are fetotoxic. ACE inhibitor fetopathy is characterized by fetal hypotension, anuria-oligohydramnios, growth restriction, pulmonary hypoplasia, renal tubular dysplasia, and hypocalvaria. Although the true frequency of adverse fetal effects has yet to be determined, because of the debilitating and lethal nature of the fetal damage when it occurs, it is our recommendation that ACE inhibitors not be used in pregnancy, particularly in the second and third trimesters.