A robust health infrastructure in every country is the most effective long-term preparedness strategy for global health emergencies. This includes not only health systems and their human resources, but also countries’ legal infrastructure for health: the laws and policies that empower, obligate and sometimes limit government and private action. The law is also an important tool in health promotion and protection. Public health professionals play important roles in health law – from the development of policies, through their enforcement, to the scientific evaluation of the health impact of laws. Member States are already mandated to communicate their national health laws and regulations to the World Health Organization (WHO). In this paper we propose that WHO has the authority and credibility to support capacity-building in the area of health law within Member States, and to make national laws easier to access, understand, monitor and evaluate. We believe a strong case can be made to donors for the funding of a public health law centre or unit, that has adequate staffing, is robustly networked with its regional counterparts and is integrated into the main work of WHO. The mission of the unit or centre would be to define and integrate scientific and legal expertise in public health law, both technical and programmatic, across the work of WHO, and to conduct and facilitate global health policy surveillance.