Smoking cigarettes during pregnancy and nursing causes considerable health damage to the fetus and to the infant during the initial growth phase. A smoking mother puts her child at considerable risk, not only of higher incidence of spontaneous abortion, premature ablatio placentae and reduced weight at birth, but also of deformities (cheilognathopalatoschisis, deformed extremities, polycystic kidneys, aortopulmonary septum defects, gastroschisis, skull deformation, etc.). Development of the Down syndrome is the subject of some controversy. These types of damage are caused by the hypoxia followed by carboxyhemoglobinemia occurring during smoking and are also observed in CO poisonings that also result in deformities. Numerous infants die during the first months of life of the so-called sudden infant death syndrome (SIDS), which can also be caused by maternal smoking and passive smoking. The contribution of nicotine to such health damage is still unclear, especially because only animal trial data are available, the applicability of which to human beings is questionable. It can be said that studies to date have revealed no deformities confirmed as having been caused by nicotine. Cardiopulmonary disturbances resulting from changes in the regulation of dopaminergic receptors are under discussion, but have not yet reached the status of a pathogenic principle. On the whole, all child health complications arising during pregnancy can be attributed almost exclusively to tobacco combustion products including the CO formed. Passage of nicotine into human milk has been confirmed in nursing smokers; passive smoking by mother and child also raises nicotine and cotinine levels in the milk and in the infant. These findings could lead to a reconsideration of smoking withdrawal therapy for pregnant women.