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.