<i>Background:</i> Maternal smoking during pregnancy is known to be associated with perinatal complications such as preterm delivery, low birth weight, and sudden infant death syndrome. <i>Objective:</i> The purpose of this study was to evaluate the influence of smoking during pregnancy on the risk of postnatal infections in preterm neonates. <i>Method:</i> We examined 80 preterm infants (gestational age 24–36 weeks), of whom 40% had been exposed to tobacco smoking during pregnancy. <i>Results:</i> Infections occurred in 31 infants. Gestational age and maternal smoking had a significant effect on the occurrence of infections (p < 0.001 and p = 0.015, respectively). An increase in maternal tobacco consumption by 10 cigarettes/day showed an odds ratio of 2.7 (95% confidence interval 1.1–6.4) for occurrence of infections. <i>Conclusions:</i> A significant association between maternal use of tobacco and the occurrence of infections in preterm neonates was found. Thus, campaigns about the damaging effects of tobacco are still warranted.