Smoking in pregnancy is unequivocally harmful to both foetal and maternal health. Earlier investigations in Norway among pregnant women who smoke have demonstrated a prevalence of smoking of around 40% and that some women stop smoking as soon as the pregnancy is confirmed (around 20%). This investigation reports only 16% smokers among pregnant women registered at 18th week of pregnancy in the two municipalities of Asker and Baerum. Average daily consumption was 8.6 cigarettes, and 65% of the women stated that they smoked more than five cigarettes per day. 97% expressed a positive interest in quitting smoking, and 76% had tried to quit earlier. 77% had a partner who was a daily smoker. An assessment of level of education showed that 82% had completed 12 years of schooling and 23% reached a higher educational level. We conclude that the relatively low incidence of daily smoking among pregnant women in these two municipalities should inspire the initiation of active intervention programmes.