Rainwater tanks are widely used as a source of drinking water in rural areas of Australia, and the consensus position among Australian health authorities is that well maintained rainwater collection systems can provide an acceptable potable water supply in situations where a disinfected reticulated supply is not available. In situations where a disinfected reticulated water supply is available, such a supply is preferable for potable use as the disinfected supply will have more reliable microbiological water quality than a rainwater tank supply. The recent drought, water restrictions in several capital cities, and ongoing concerns about the sustainability of water supplies has resulted in increased interest in the installation of rainwater tanks in urban areas. Given the potential that this may lead to increased consumption of rainwater even in areas where a treated public drinking water supply is available, health authorities are concerned that the potential health risks should be better documented and understood, particularly with respect to any differences in rainwater quality that may exist between urban and rural settings.