Abstract: Invasive cacti have been identified by the natural resource management community as a major threat to the biodiversity and primary production values of the rangelands of Australia. A number of species of cacti (principally members of the Opuntia and Cylindropuntia) have serious infestations in semi arid and arid areas of all mainland states. These weeds have proven difficult and very costly to control using chemicals and currently have few effective biological controls. The Rangelands NRM Alliance has identified the threat that invasive cacti pose and has supported the formation of the Australian Invasive Cacti Network. The network objective is to raise awareness of the threats posed by this group of weeds and provides a conduit for the exchange of information on taxonomy, biology and best practice control techniques.