Kanagawa Prefecture became the first subnational government in Japan to implement an ordinance for the prevention of exposure to secondhand-smoke in public facilities. The ordinance aims to protect people from the negative health impacts of secondhand smoke; however, it has wide exemptions especially for hospitality and leisure business establishments. In addition, designated smoking areas are allowed in all public facilities, in contravention of the WHO Framework Convention on Tobacco Control. Nevertheless, its rapid enactment benefited from the political leadership of the governor as well as intensive communication between the government and a wide range of stakeholders in Kanagawa and beyond. The smoke-free efforts of Kanagawa could facilitate smoke-free action by other subnational and national governments for healthier environments.