Abstract Second and third hand smoke exposure increases risk for a number of cancers and other adverse health effects in smokers and non- smokers. Public health campaigns have reduced smoking in many types of public enclosed spaces, but the residential environment remains an important area for risk reduction. In multi-unit housing, significant exposure due to drift between units has led to market and policy efforts to promote smoke-free multi-unit housing options. Public housing authorities have implemented smoke-free policies in greater numbers since the 2009 HUD Healthy Homes Strategic Plan, but the implementation of smoke-free policies in public housing, which must serve diverse communities of low income families, disabled, and elderly residents, presents ethical and logistical challenges. The Philadelphia Housing Authority is the fourth largest housing authority in the US, serving over 80,000 residents, and is among the largest to implement smoke-free policies. The Drexel School of Public Health, in partnership with the Philadelphia Department of Public Health and with funding from the Centers for Disease Control and Prevention, has conducted a longitudinal mixed methods evaluation of the implementation process. Our formative evaluation began with in-depth interviews and focus groups with residents, including smokers and non-smokers, as well as PHA staff, policy leaders, and local tobacco control stakeholders, as well as ethnographic observations of the tobacco use culture in diverse housing communities in Philadelphia. We then conducted baseline interviews with a sample of residents in four communities, and conducted air nicotine monitoring in both residents' homes and in public areas, including elevators, laundry rooms, hallways, and lobbies. During implementation, we will continue to monitor resident knowledge, attitudes and tobacco related behaviors, as well as tobacco use in public and home environments. Results will be discussed in the context of community behavior change, and tobacco control policies for high risk, low resource communities. As well, the Philadelphia example will be compared to other cities and communities, and to the broader theory of implementation science for public health. Citation Format: Ann Carroll Klassen. Dissemination and implementation of cancer prevention policies: The example of smoke-free public housing. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr CN03-01.