PaDIL (Pests and Diseases Image Library) is an Australian Government initiative. Fundamental to minimising risks of pests crossing national or internal borders is the ability to rapidly diagnose them accurately and efficiently. Activities aimed at lowering risks eg surveillance, or managing plant pests if they cross borders require knowledge of what they are dealing. Also international obligations require that pests of concern are defined when developing phytosanitary measures to facilitate the movement of goods. Added to the complexity of this task are two factors: the majority of pests encountered are not local, hence diagnosticians often require a world-wide knowledge of the pests; and there is a worldwide decline in availability of plant pest diagnosticians and taxonomists. To begin to address these issues a virtual image library (PaDIL) was developed. PADIL is a website providing high quality, colour, diagnostic images and basic information on plant pests (taxonomy, distribution, hosts). No software downloads are required to make full use of the site. The software allows the user multiple query points (name, bioregion, host) and the ability to build user-defined image tables which combine species and image characters chosen by the user. PaDIL is freely accessibly and images are available for non commercial use. Currently, there is information on over 1200 plant pests. The primary target audience is plant biosecurity diagnosticians with some level of experience; however, the image-based website can be easily used by specialists and non-technical persons, and it is intended that over the next 4 years to build this non-specialist capacity.