While much is known about the impact of law and public policy, we know considerably less about their antecedents. Theories of policy adoption suggest that a variety of policy inputs help to shape legislative change. This research considers the enactment of municipal smoking bylaws in Canada between 1970 and 1995. The emergence of second-hand smoke (SHS) has been offered as a viable explanation for the increased enactment of local smoking restrictions. A number of indicators confirm the rising public health concern around SHS. Using Health Canada data on municipal smoking bylaw enactment in Canada, this paper employs an event history analysis to trace the role of four indicators of the increased recognition of SHS as a public health concern-scientific research, parliamentary debate, print media, and health advocacy. Findings indicate that the print media and health advocacy play the strongest role in explaining the increase in the adoption of municipal smoking bylaws in Canada. Results lend support to the quantitative study of the policy adoption process and to theories of policy making that consider multiple influences on policy adoption.