Objective: To describe recent trends in the diagnosis of HIV infection in Australia. Methods: National HIV surveillance data from 1993 to 2006 were analysed with a focus on geographic differences by HIV exposure route and late presentation (HIV within 3 months of a first AIDS-defining illness or a CD4 count of less than 200 cells μL^–1). Results: In 1993–99, the number of HIV diagnoses declined by 32%, and then increased by 39% from 1999 to 2006. From 2000 onwards, rates increased significantly in Victoria, Queensland, South Australia and Western Australia. The most frequently reported routes of HIV exposure were male to male sex (71%) and heterosexual contact (18%), and the population rate of diagnoses have increased in both categories. Among the cases reported as heterosexually acquired (n = 2199), 33% were in people born in a high-prevalence country and 19% in those with partners from a high-prevalence country. Late presentation was most frequent in heterosexually acquired infections in persons who had a partner from a high-prevalence country: 32% compared with 20% overall. Conclusions: Recent increases in annual numbers of HIV diagnoses in Australia underline the continuing need for HIV-prevention programs, particularly among men having male to male sex. Early diagnosis and access to care and treatment should also be emphasised, as a substantial proportion of people with HIV infection are unaware of their status until late in the course of disease.