Loss of natural ecosystems and of species is a fact of life in densely populated cities. Some species can prosper in an urban environment, but urban populations of species are generally too small to have a significant influence on their overall conservation status. Urban biodiversity is important nevertheless: it can build an appreciation among city dwellers of biodiversity and its conservation, enhance recreational space, and serve practical functions such as helping to cool the air and reduce stormwater and pollutant run-off. Visionary urban design can significantly improve the status and trends of biodiversity in cities and their surrounding regions. Australian biodiversity science has expended too little effort on the urban environment, and information on which to base urban biodiversity strategies is generally lacking. Supporting urban communities in Australia with information and monitoring tools will benefit biodiversity, and help connect Australians with the environment that sustains them.