Internationally, there have been persistent complaints that the policy capacity of governments has declined. This critique is widely accepted, including in Australia, but for the most part, such claims are assertions, made without reference to empirical evidence and data. This introduction to the Special Issue examining the Policy Advisory Capacity of the Australian Public Service considers these assertions and proposes an approach and methodology to test the discourse of declining policy capacity in Australian federal government. It introduces six case studies from across the spectrum of the Commonwealth government's responsibilities. The Special Issue concludes with an article by Evert Lindquist and Anne Tiernan assessing the ability of the APS to support decision-making through its policy advising functions and its preparedness to meet the challenges of 21st century governance.