This study investigates the implementation of a restrictive smoking policy in decentralized worksites. A model which includes four elements-concept, context, process, and outcomes-is used as a framework for identifying characteristics that influence implementation. The organization studied was a state human services agency with approximately 400 worksites spread across 12 geographic regions. Quantitative data collection included three cross-sectional surveys of employees and supervisors administered before and after the date the policy became effective. Qualitative data were collected from three sources, including written comments on surveys, focus groups, and structured interviews with supervisors and top administrators. Tabular analyses and one-way analyses of variance were used to analyze quantitative data. Qualitative data were examined for key themes and have been used to elucidate findings. Those characteristics related to concept, context, and process which appeared to have the strongest influence on expected and unexpected outcomes of the restrictive smoking policy were degree of policy restrictiveness, job characteristics, perceived level of participation in formulation and implementation, and support of supervisors responsible for day to day enforcement. In particular, in this decentralized organization, lack of participation was found to underlie many of the problems experienced in implementation. The practical implications for developing and implementing a worksite restrictive smoking policy are discussed.