Mental health problems in children and adolescents have a high incidence in Peru and worldwide. However, studies on the psychological repercussions of the pandemic of Covid-19 on children and adolescents in Peru are insufficient. The general objective was to identify the magnitude of the major mental health problems in the child and adolescent population in Lima (Peru) related to Covid-19. This study was descriptive-transversal. The sample was of 2639 children and adolescents. We used the following instruments: demographic and socioeconomic file; Questionnaire on experiences, behaviors and impact related to Covid-19; International Neuropsychiatric Interview for Children and Adolescents; Family Violence Questionnaire; “How is your Family” Questionnaire; Adolescent Family Process Scale; Parental Behavior Inventory and Questionnaire on determinants of access to health services in Peru. ...