Introduction: Adolescence is one of the stages in life most affected by suicide. In Peru, 22% of suicides occur in people 10 to 19 years old. However, mental health overall and factors associated with suicidal behaviors have not been well studied. Objective: To determine the prevalence of suicidal behaviors (ideation and ideation plus suicidal planning) and associated factors in Peruvian adolescent students. Methods: A cross-sectional study analyzing data from the Global School-based Student Health Survey for Peru in 2010 was conducted to measure the prevalence of suicidal behaviors (ideation and ideation plus suicidal planning) and associated factors in Peruvian adolescent students. Results: Of the 2521 students evaluated, 19.9% (95% CI: 17.8 to 22.2) presented suicidal ideation and 12.7% (95% CI: 11.1 to 14.5) presented suicidal planning in the last 12 months. Females had a higher prevalence of both ideation (27.5%, 95% CI: 24.9 to 30.4) and ideation plus suicidal planning (18.5%, 95% CI: 16.4 to 20.7). Multivariate analysis found that being female, having little parental support, having felt loneliness, having suffered from physical aggression, having been bullied, and alcohol consumption, were associated with ideation and ideation plus suicidal planning in adolescent students. Conclusion: Ideation and ideation plus suicidal planning is a problem in the Peruvian adolescent population and is associated with several factors. Strategies are needed to identify and register suicide in adolescents in Peru and to develop prevention programs.