This study examined the association between maternal smoking during pregnancy and maternal behavior during mother-infant interactions during the neonatal period. Participants included 84 mother-infant dyads (43 cigarette-exposed and 41 nonexposed) who were recruited after birth and assessed at 2 to 4 weeks of infant age. Results indicated that mothers who smoked during pregnancy had higher levels of maternal insensitivity (MI) and lower levels of maternal warmth (MW) during interactions with their infant even after controlling for demographics and pregnancy alcohol use. Maternal anxiety and hostility mediated the association between smoking and MI and maternal anger mediated the association between smoking and reduced MW. In addition, there was an interaction between infant gender and maternal smoking for MW with smokers displaying less warmth to boys during interactions. (Contains 4 tables and 1 figure.)