Introduction: family functionality is a set of interpersonal relationships of the adolescent, which need an emotional stability and the environment in which they can safely explore an unknown world, therefore. Objective: to determine family functionality and nursing intervention in adolescents of an educational institution in an area of Lima. Methods: it is a quantitative-descriptive, cross-sectional study, with a total population of 571 participants who answered a questionnaire of sociodemographic data and the family APGAR instrument. Results: in the results, 303 (53,1 %) of the adolescents have severe familial dysfunction, 155 (27,1 %) moderate, 5 (0,9 %) mild and 108 (18,9 %) good family function. Conclusions: it is concluded that family interventions should be carried out that allow family union and thus be able to improve the psycho-affective health of the adolescent. © 2023; Los autores.