In this study of 25,102 deliveries, smoking increased the risk of stillbirth and infant death. Because of prospective collection of information about maternal lifestyle factors and sociodemographic factors, we could adjust for a number of potential confounders, including alcohol intake during pregnancy. Apparently, these variables could not explain our findings. However, information about socioeconomic variables was missing in about one third of all women, which may constrain the possibility to adjust fully for these factors. We found a higher risk associated with smoking than in previous studies that have found significantly increased mortality in infants of smokers (7, 10, 12, 13). This may be due to the fact that our study was conducted in a homogeneous population with low overall mortality, reflecting lower prevalence of competing risks.