The aim of this study was to characterise the AIDS presenters diagnosed between 2000 and 2008 in Legnano (Italy), and describe their initial response to highly active antiretroviral therapy (HAART) and trends over time. Seventy-six (48.7%) of 156 patients diagnosed as having AIDS in the period 2000-2008 were AIDS presenters. The proportion of AIDS presenters increased from 23.8% in 2000 to 70.6% in 2008 (p = 0.009). The major risk factors were heterosexual transmission and a foreign place of birth, and did not significantly change over time. The median CD4+ cell count at diagnosis was 30 cells/microl and the median level of HIV RNA was 5.38 log copies/ml, with no differences between the transmission risk groups. Fifteen AIDS presenters died of AIDS-defining diseases; the others started HAART (72% with 2 NRTIs + boosted PI), and 40% after a drug resistance test. The median duration of the initial HAART was 107 days. After three months, 34% of the patients had undetectable HIV-RNA levels and the median CD4+ cell count was 140 cells/microl; the corresponding figures after 12, 24 and 48 months were respectively 84%, 82.3% and 94.1%, and 310, 370 and 380 cells/microl. In conclusion, the AIDS presenters were mainly heterosexual men and immigrants. Their proportion increased significantly over time, and a substantial proportion maintained an immunovirological response to HAART.