Prospective and retrospective access block hospital intervention studies from 1998 to 2008 were reviewed to assess the evidence for interventions around access block and ED overcrowding, including over 220 documents reported in Medline and data extracted from The State of our Public Hospitals Reports. There is an estimated 20-30% increased mortality rate due to access block and ED overcrowding. The main causes are major increases in hospital admissions and ED presentations, with almost no increase in the capacity of hospitals to meet this demand. The rate of available beds in Australia reduced from 2.6 beds per 1000 (1998-1999) to 2.4 beds per 1000 (2002-2007) in 2002, and has remained steady at between 2.5-2.6 beds per 1000. In the same period, the number of ED visits increased over 77% from 3.8 million to 6.74 million. Similarly, the number of public hospital admissions increased at an average rate of 3.4% per year from 3.7 to 4.7 million. Compared with 1998-1999 rates, the number of available beds in 2006-2007 is thus similar (2.65 vs 2.6 beds per 1000), but the number of ED presentations has almost doubled. All patient groups are affected by access block. Access block interventions may temporarily reduce some of the symptoms of access block, but many measures are not sustainable. The root cause of the problem will remain unless hospital capacity is addressed in an integrated approach at both national and state levels.