Objective: Smoking is the largest cause of preventable illness in the United States, the United Kingdom, Canada, Australia, and many other countries. Smokers with mental illness smoke significantly more than those without mental illness and therefore experience even greater smoke-related harm. Internationally, there is increasing pressure on psychiatric inpatient settings to adopt smoke-free policies. This study examined smoke-free policies across psychiatric inpatient settings in Australia and thereby identified factors that may contribute to the success or failure of smoke-free initiatives in order to better inform best practice in this important area. Methods: Semistructured in-depth telephone interviews were conducted with 60 senior administrators and clinical staff with direct day-to-day experience with smoking activities in 99 adult psychiatric inpatient settings across Australia. Quantitative data were analyzed using descriptive statistical analysis and Pearson's chi square correlations measure of association. Results: Factors associated with greater success of smoke-free initiatives were clear, consistent, and visible leadership; cohesive teamwork; extensive training opportunities for clinical staff; fewer staff smokers; adequate planning time; effective use of nicotine replacement therapies; and consistent enforcement of a smoke-free policy. Conclusions: A smoke-free policy is possible within psychiatric inpatient settings, but a number of core interlinking features are important for success and ongoing sustainability.