Reducing the prevalence of smoking in pregnancy is a priority target for health care. We administered a semi-structured questionnaire to mothers in an inner city general practice who were given brief anti-smoking advice during routine antenatal care. Of a cohort of 113 mothers, 52(46%) reported smoking at the start of pregnancy. Six(12%) of these 52 smokers reported no change in smoking habit during pregnancy; 24(46%) cut down; 12(23%) stopped; 10(19%) increased their cigarette consumption. Of the 52 smokers, 41(79%) believed smoking was harmful to an unborn baby, yet 30(73%) of these women continued smoking. Almost all recalled having been given anti-smoking advice by the GP and/or hospital. There is an urgent need to identify more effective methods of reducing smoking in pregnancy.