Correspondence to Roberta L Hall, Department of Anthropology, Oregon State University, Corvallis, OR 97331, USA. Abstract Objective -To describe patterns of tobacco use and non-use in buildings managed by a sample of Northwest US Indian tribes, and at buildings of com parable local government offices in ad jacent communities, at baseline (1991) and after half of the tribes had received an intervention aimed at upgrading tobacco control policies (1993). Methods Rapid assessment procedures consisting of an objective check list of tobacco related artefacts, detailed obser vations of tobacco practices in various settings, and conversations with local people concerning tobacco practices; comparison of observations made in 1991 and 1993. Results Tobacco related artefacts and social acceptance of personal tobacco use decreased in indoor areas, particularly in official tribal offices. Locations that ap pear resistant to tobacco control in both Indian and non-Indian areas were out door porches and entry ways, parking lots, restaurants, bingo halls, casinos, and offices of natural resource businesses such as forest products. Conclusions Observations made in field visits provided investigators with a de scription of the context within which tobacco control by Indian tribal govern ments is expressed, and identified social environments where tobacco control has been effective and those that need ad ditional attention.