Introduction. In industrialized countries, the availability of highly active antiretroviral therapy (HAART) caused a slow but substantial ageing of the AIDS epidemic mainly due to the longer survival of persons with HIV/AIDS which has turned HIV into a manageable, chronic disease. The number of older people with AIDS is growing in many European countries. We described the impact of AIDS among persons aged 50 years or more in Italy and compared the characteristics of these cases with those of persons diagnosed with AIDS at an age younger than 50. Methods. The source of data was the Italian AIDS Registry, from 1982 to 2011. We defined "older" persons those aged 50 years or more, and younger individuals those aged less than 50 years. We built two multivariate logistic regression models: the first one to identify factors associated with being older, and the second one to identify AIDS-defining diseases correlated with being older. Variables with a P value of < 0.05 were entered in the model. Results. Of the total AIDS cases, 10.5% were among persons older than 49 years. This proportion progressively increased from 0.0% in 1983 to 26.4% in 2011. Among older cases, the incidence of AIDS was 2.0 per 100 000 residents in 1996, then decreased to 1.4 per 100 000 in 2000 and levelled off around 1 per 100 000 residents until 2011. Compared to younger cases, older cases were more frequently males, Italians, diagnosed with AIDS in recent years, residing in Northern or Central Italy, non-injecting drug users, and late testers. Discussion. These findings stress the need for physicians to consider carefully the possibility of HIV infection among older individuals not to miss the opportunity to deliver prevention messages, offer HIV testing, and make an early diagnosis.