This paper presents a detailed case history of the 1976/77 advertising campaign to persuade people in Britain against drinking and driving. It deals firstly with the background to the campaign and the role of research in its development. The main body of the paper then deals with the evaluation of the campaign covering general considerations, the research methodology, research results and accident statistics, and the impact of the research on the 1977-78 campaign. Following this there is a detailed discussion of a methodological experiment on quota versus random sampling techniques that was incorporated into the research design. A short final section points conclusions to be drawn from this case history in relation both to aspects of the evaluation of campaigns of social persuasion.