In the closing decade of the 20th century the myriad challenges posed by infectious disease in a globalized environment began to be re-conceptualized as threats to national and human security. The most widely applied model for identifying and responding to such threats is securitization theory, as proposed by the Copenhagen School. Although its analytical framework is generally accepted, its utility remains contested; especially in non-European and non-state settings. The papers in this special edition have several aims: (1) to analyse ways by which Asian states and international organizations have identified health challenges as security threats, (2) to draw upon the securitization model as a way of understanding the full extent to which these states and international organizations have responded to the health threat, and (3) to identify areas where the theory might be strengthened so as to provide greater analytical clarity in areas of health security. This paper acts as a broad introduction to a set of papers on 'Unhealthy governance' and explores some of the key findings from the subsequent papers.