This paper analyses how the policy process is shaped by networks of influence. It reports on a study of health policy influence in Victoria, describing the theoretical framework and the methods used. Social network analysis, combined with interviews, was used to map the network’s structure, identify important individuals and examine issues seen to be important and difficult. Which issues an individual is interested in are related to where that person sits within the network. It also demonstrates how influence structures the health policy agenda, and provides insights for public health practitioners who aim to influence policy.