Carollyne Gomes de FranÃĤa Valle, Ines Silva de Almeida, Ann Mary Machado Tinoco Feitosa Rosas, Angela Maria e Silva To uncover the meaning of the first sexual intercourse to the adolescent. Descriptive and qualitative study with a phenomenological approach guided by Martin Heidegger references. The background/scenario used is (was) the first response ambulatory specialty clinic at the Nucleus of Teenage Health Studies (Núcleo de Estudos da Saúde do adolescente or NESA) at Rio de Janeiro State University (Universidade do Estado do Rio de Janeiro, UERJ). Data were collected in January and March of 2014. The subjects were 13 adolescents between the ages of 14 and 20. The project was approved by CEP/HUPE/UERJ, CAAE: 01270112.9.0000.5259. The analysis uncovered the facticity, the being-with, and revealed the in authenticity and awkwardness of being-adolescent at sexarche. Their first sexual experiences appeared to be steered by hearsay. The results lead to reflection on the integral care of the adolescent, because a new approach from the health services as well as a new stance/attitude from the professionals is needed, taking into consideration their sexual and reproductive rights.