Objective: To identify factors associated with attitudes towards violence (ATV) in schoolchildren from public educational institutions (EI) located in marginal urban areas of Metropolitan Lima in 2019. Materials and methods: Observational, descriptive and transversal study. The sample was made up of adolescents from 10 mixed-gender EIs enrolled between the sixth grade of primary school and the third year of secondary school. The questionnaire of attitudes towards violence (CAHV-25) was used. During the bivariate analysis, the Spearman Correlation Coefficient, the Mann-Whitney U test and the Kruskal-Wallis H test with Dunn’s post-hoc adjusted by Bonferroni were used. To determine the associated factors, multivariate analysis was performed using negative binomial regression model. Results: 45.1% of the schoolchildren were female and 87.3% received information on school bullying. In the bivariate analysis, statistically significant differences were found between the ATV scores and age (p = 0.003), sex (p < 0.001), having a social network account (p = 0.009) and year of study (p < 0.001); however, in the multivariate model, the factors associated with the total ATV scores were age (p = 0.012) and sex (p < 0.001). Conclusion: The factors associated with ATV in schoolchildren from public EIs were age and sex, these findings would indicate the need to consider the gender perspective in the analysis of school violence and differentiate interventions according to age.