Journal of Environmental Engineering and Landscape ManagementPublication details, including instructions for authors and subscription information:Abstract. A number of legislative bodies in Europe have already made or are currently considering making policy decisions on the issue of smoking in public places. Policy alternatives have been discussed in Town and Country Planning (2002). In the last decade, the scientific evidence relating to this debate has been reported in a diverse range of publications such as the British Medical Journal, Indoor Air and The Chartered Institution of Building Services Engineers journal. On inspection much of this reporting concludes negatively on the performance of ventilation systems. In this paper, a critical review is undertaken of the "before and after smoking ban" study papers. This paper aims to critically review the findings of these studies in relation to ventilation and draw some working conclusions from these studies.