This article presents the characteristics of older adults (aged 50 and older) who learned of their HIV-positive status in 2016, comparing them to those of adults aged 25 to 49 based on mandatory HIV infection reports. In 2016, the number of older adults who learned of their HIV-positive status was estimated at 1,184 [95% CI: 1,094–1,274], representing 20% of all new diagnoses. This number increased steadily between 2008 and 2014, with the increase primarily among men who have sex with men (MSM) and foreign-born women infected through heterosexual intercourse. Older adults who discovered their HIV-positive status in 2016 differed from younger individuals in that they had a lower proportion of MSM and a higher proportion of heterosexuals born in France. The proportions of people who had never been tested for HIV before discovering their HIV-positive status and those diagnosed at an advanced stage of infection were significantly higher among older adults than among those aged 25–49 (48% vs. 42% and 38% vs. 26%, respectively). The proportion of recent infections among older adults (28%) indicates risk-taking behavior in this age group. This insufficient level of testing among older adults can be explained by a lower perception of the risk of HIV infection, both among the individuals themselves and among healthcare professionals, even though exposure to the infection persists beyond age 50. It is therefore important that prevention efforts include this population.