Babies of mothers who smoke during pregnancy tend to be born underweight but are at risk for pediatric obesity. Maternal feeding practices, maternal disordered eating, and child temperament were assessed as potential mediators of early weight gain in babies of smoking and non-smoking mothers. The BMIs of babies of 88 smoking and 107 non-smoking mothers were recorded at birth and reported one year later. Mothers self-reported on disordered eating and child feeding practices, and on their infants' temperament. Babies of smoking mothers had lower BMI at birth but not at age one. For babies of non-smoking but not for those of smoking mothers, BMI at birth predicted BMI at age one. Smoking mothers' disordered eating and pressure for children to eat predicted their babies' BMI at age one. In the non-smoking group only, there were significant correlations between babies' temperamental difficulties and babies' BMI at age one. In contrast to non-smoking mothers, smoking mothers tend to pressure their babies to eat, and not to feed them in response to their distress. This interim picture may provide insight into the transition of the children of smoking mothers from underweight newborns to children classified as overweight.