Surveys of Turkish speaking people in London found 74% of men and 45% of women were smokers, and knowledge of the health effects of smoking was low. Camden and Islington Health Authority has a substantial Turkish community. We report an economic evaluation of a community smoking cessation intervention, aimed at the Turkish community, undertaken by Camden and Islington Health Promotion Agency. The intervention aimed to highlight the dangers of smoking, and to reduce the amount smoked and the number of current smokers. It included a play, a poster and media campaign, and purpose-designed leaflets. A panel survey of the Turkish population determined smoking habits, attitudes to smoking and knowledge about the health effects at baseline and 12 months. The intervention effect was estimated from the changes between baseline and final surveys. To allow for the non-response to the second survey we analysed effectiveness in two ways: first by assuming that the responders represented the true situation, and secondly by making a more pessimistic assumption that there was no change in the non-responders. Fifty-seven per cent of the Turkish population were smokers at baseline, compared with 39% in the general population of Camden and Islington. Levels were particularly high in younger women. At follow-up there was a net reduction in smokers of 6.4% [95% confidence interval (CI) 0-13.6%] in responders. When all study subjects were included the net reduction was 2.9% (CI 0-6.3%). Most quitters were light smokers to start with. At follow-up, 51% of respondents recognized at least one of the Turkish language interventions. The estimated cost-effectiveness of this intervention was 105 pound (range 33-391 pound) per life year gained. Campaigns targeted at groups with high smoking prevalence may be more cost-effective than general population campaigns.