When HIV transmission from mother to child occurs, one of the major concerns is revealing the diagnosis to the infected children, something that could be experienced as a biographical turning point. The objective is to explore the effect of the disclosure of the diagnosis as experienced by adolescents who have been living with HIV since their birth. Twenty-nine HIV-positive young (aged from 10 to 18) agreed to a semi-structured individual interview focussed on the revelation of their serologic status. The data thus gathered was submitted to a content analysis (Paillé and Mucchielli, 2005; Sabourin, 2008). The disclosure of the serologic status runs through three stages: 1) that of a hidden reality, where the adolescents are unaware of their serologic status; 2) that of a reality which is finally disclosed when, at about the age of 11, they learn that they have an HIV infection; and 3) that of a reality they need to progressively integrate, where its disclosure becomes a participating factor in the construction of their personal and social identities. The disclosure becomes an extension of their biographical continuity by legitimizing their ARV treatments, at a time when they appear to be contemplating gradual changes with respect to their private lives and personal sexuality.