The Australian Sentinel Practice Research Network (ASPREN) is a national network of general practitioners (GPs) who collect and report data on selected conditions, including influenza-like illness (ILI). The Australian Government Department of Health and Ageing initiated an evaluation of ASPREN, aiming to assess its potential to contribute to surveillance of emerging infectious diseases including pandemic influenza. System attributes and utility for decision-making were elucidated from stakeholder surveys. ASPREN ILI data for 2002 to 2004 were compared with ILI data from South Australia and New South Wales. In 2004, 50 GPs participated in the ASPREN surveillance, with proportionately more in New South Wales (30%) and South Australia (30%) than in other states. The majority (78%) of GPs were in metropolitan practices. Compliance with the manual data collection system was not optimal, nor consistent by state. ASPREN ILI data compared favourably with that of other surveillance systems. No formal structures were in place by which to assess data trends, provide alerts or initiate public health action. To maximise the contribution to biosecurity surveillance, ASPREN would require targeted GP recruitment to achieve geographic representativeness; exploration of alternative technologies for data collection and reporting; provision of committed resources adequate for system operation; and negotiation with state-based public health reference laboratories to provide laboratory support. The main potential of ASPREN is to permit rapid dissemination of a syndromic case definition and acquisition of nationwide community level clinical presentation data. These evaluation findings will be used to inform redevelopment of ASPREN as part of the Biosecurity Surveillance System project.