Objectives: To determine if there were any differences in antiretroviral treatment (ART) use across the three eastern states of Australia, New South Wales (NSW), Victoria and Queensland, during the period 1997 to 2006. Methods: We used data from a clinic-based cohort, the Australian HIV Observational Database (AHOD), to determine the proportion of HIV-infected patients on ART in selected clinics in each state and the proportion of treated patients with an undetectable viral load. Data from the national Highly Specialised Drugs program and AHOD were used to estimate total numbers of individuals on ART and the proportion of individuals living with HIV on ART nationally and by state. Data from the HIV Futures Survey and the Gay Community Periodic Survey were used to determine the proportion of community-based men who have sex with men on ART. The proportion of patients with primary HIV infection (PHI) who commenced ART within 1 year of diagnosis was obtained from the Acute Infection and Early Disease Research Program (AIEDRP) CORE01 protocol and Primary HIV and Early Disease Research: Australian Cohort (PHAEDRA) cohorts. Results: We estimated that the numbers of individuals on ART increased from 3181 to 4553 in NSW, 1309 to 1926 in Victoria and 809 to 1615 in Queensland between 2000 and 2006. However, these numbers may reflect a lower proportion of individuals living with HIV on ART in NSW compared with the other states (37% compared with 49 and 55% in 2000). We found similar proportions of HIV-positive men who have sex with men participants were on ART in all three states over the study period in the clinic-based AHOD cohort (81–92%) and two large, community-based surveys in Australia (69–85% and 49–83%). Similar proportions of treated patients had an undetectable viral load across the three states, with a consistently increasing trend over time observed in all states. We found that more PHI patients commenced treatment in the first year following HIV diagnosis in NSW compared with Victoria; however, the sample size was very small. Conclusions: For the most part, patterns of ART use were similar across NSW, Victoria and Queensland using a range of available data from cohort studies, community surveys and national prescription databases in Australia. However, there may be a lower proportion of individuals living with HIV on ART in NSW compared with the other states, and there is some indication of a more aggressive treatment approach with PHI patients in NSW compared with Victoria.