Introduction: Suicidal ideation and deliberate self-harm prevalence has markedly increased among youngsters over the past two decades. The objective of the work was to determine the prevalence and factors associated with deliberate self-harm and suicidal ideation in students of Costa Rica. Material and Methods: Descriptive and cross-sectional study was conducted. Questionnaires were applied to 2284 students in Costa Rica to collect data on individual, family and social factors related to self-harm behavior and suicidal ideation. Data were analyzed by using SPSS program to estimate frequencies and multivariate models which were tested with different variables. All procedures performed were in accordance with ethical standards. Results: Around 18.2% of the young people presented suicidal ideation and 10.2% self-harm behavior. "Bullying" was the variable most strongly associated with suicidal thoughts and deliberate self-harm. Conclusions: Efforts should be made to promote positive school climates where the practice of bullying is not allowed.