The aims of this study were to document the extent of cigarette smoking and alcohol consumption by Victorian women during pregnancy and relate the use of cigarettes and alcohol to various measures of pregnancy outcome. The study found that 24 per cent of women smoked during pregnancy and smoking was more common amongst younger women; 99.5 per cent of women drank, on average, less than two standard drinks per day and older women were more likely to be drinkers than younger women; 3.6 per cent of women reported at least one episode of binge drinking during pregnancy. There was an increasing trend in the proportion of low birthweight (>2500g) infants with increasing use of tobacco and a dose-dependent reduction in mean birthweight. Drinkers were less likely to have a pre-term or low birthweight infant than abstainers and babies born to drinkers had a higher mean birthweight than babies born to abstainers. The results of our study did not suggest that drinkers were at increased risk of delivering an infant with a congenital malformation, however heavy drinking was very uncommon in the studied population.