This research evaluates a healthy work organization intervention implemented in a retail setting. Using a participatory process, employee teams in 11 intervention stores developed customized plans for improving work organization at their sites. Ten comparable stores served as controls. Employee surveys were administered prior to the intervention and twice again at 12-month intervals. Business results were compiled monthly for each store. The baseline data were used by the teams to identify needs and establish action priorities for their stores. Most study outcomes declined across time for all stores, due primarily to internal corporate events and a generally adverse economic environment. However, the intervention process appeared to buffer some of these declines; intervention stores fared better in terms of selected aspects of organizational climate and psychological work adjustment. Intervention stores also performed better than controls on general indices of perceived health and safety and two of the four business outcomes: employee turnover and sales per labour hour. These results are discussed in terms of the challenges involved in evaluating organizational-level interventions in work settings.