Two surveys were conducted among pregnant women throughout England, before (n = 625) and after (n = 607) a mass media campaign on smoking and pregnancy targeted at women aged 15-24 years, in the social grade C2DE. The majority of the post-campaign sample recalled having seen at least one of the campaign's series of press advertisements. There was a significant increase among this sample in those considering smoking to be very dangerous to the unborn child, in those understanding the term passive smoking and in those considering passive smoking to be very dangerous. During the campaign there was a 14% increase in the number of calls to a cessation helpline from pregnant women. Over the campaign there were no significant changes in smoking prevalence and consumption among pregnant women or partners or in the numbers of partners offering suggestions to pregnant women about their smoking behaviour.