This paper describes a cohort of people living in Victoria, Australia, diagnosed with incident HIV infection and identified through routine HIV surveillance. All HIV diagnoses notified to the Victorian HIV Registry between January 1997 and September 1998 were included. Infections were classified as incident if there was a prior negative test and/or seroconversion illness within 12 months of the first positive HIV test. During the study period there were 277 notifications received of which 70 (25%) were incident infections (seroconversions). People with incident infection were aged 36 years (+/- 10), from an Anglo background (76%) and living in Melbourne (91%). Seroconverters were more likely to have acquired their infection in Victoria (76%), through male-to-male sexual contact (86%), and from casual or anonymous partners (67%). Cohorts of individuals with incident HIV infection provide a valuable resource for understanding the dynamics of HIV acquisition and natural history of the infection.