In 2010, Waterloo Region Housing (Canada) enacted a smoke-free (SF) housing policy that made all new leases in their community-housing portfolio (2722 units) 100 % SF. Existing lease holders were 'grandfathered'-meaning tenants could still smoke in their homes. A survey to measure support for the policy and how the policy had impacted smoking behaviour was delivered to all 2722 households in the Waterloo Region Housing portfolio in 2010 (pre-policy), 2011 and 2013 (post-policy). The proportion of households that completed the survey was 26 % (n = 717) in 2010, 25 % (n = 685) in 2011, and 23 % (n = 619) in 2013. Support for the SF housing policy was 72 % pre-enactment (2010), and increased to 78 % in 2011 and 79 % in 2013; however, most smokers do not support the policy. In 2010, prior to the SF policy, 65 % of tenants who smoke reported someone smoked inside their home; in 2013 this was reduced to approximately half of smokers (52 %). In 2013, 44 % of smokers reported smoking outside more often than before the SF policy was enacted, almost half of tenants with a smoke-free lease (46 %) and more than a third of tenants who have a grandfathered lease (34 %) reported they smoke less since the smoke-free policy. There has been no significant change in the proportion of respondents (>50 %) who reported being exposed to second-hand smoke in their home. This SF housing policy is associated with increased reported outdoor smoking and reduced smoking. Smoke-free policies may support smokers interested in quitting.