The analysis relies primarily on data from the Australian Prison Census. Overall, the imprisoned population in Australia has increased by an average of 4.2 percent per year from 1982 to 1998. The population of imprisonable age (age 18 years and over) , however,has increased only by an average 1.6 percent per year during the same period. The annual growth rate of the prison population in Australia is twice that recorded in England and Wales, but is only half that of the United States over the 1981-97 period. This analysis concludes that besides demographic differences among Australian jurisdictions, other factors affect the size of inmate populations and imprisonment rates. These include policies that favor imprisonment for offenses that could otherwise be sanctioned with less severe forms of punishment; policies that impose tougher sanctions on convicted criminals; inmates spending longer portions of their sentences in prison; an augmented flow of individuals being processed by police due to legislative changes; and variations in crime rates. Information and data are also provided on the legal status of inmates, length of sentence, demographic composition, and the imprisonment of indigenous Australians. 2 figures and 11 references