We describe the tobacco industry's response to the American Stop Smoking Intervention Study (ASSIST). Tobacco industry documents from the University of California, San Francisco/Legacy Tobacco Documents Library and industry Web sites were analyzed. LexisNexis and the Library of Congress's Thomas Web site were searched for legislative history. We found that the tobacco industry considered ASSIST a major threat because of its emphasis on policy and creation of local tobacco control infrastructures. The industry mobilized resources for a well-coordinated attack on ASSIST. Although industry executives were sometimes frustrated in their efforts, they ultimately had a chilling effect on ASSIST. This evidence suggest that tobacco control advocates should expect a vigorous response from the tobacco industry to policy advocacy efforts, particularly at the local level.