Objectives: Suicide is one of the leading causes of death in adolescence, and the second most common cause of death among young people. The objective of this study was to identify trends in suicidal ideation by sex and ascertain factors associated with this outcome. Methods: Secular trend study with statewide coverage conducted at 5-year intervals, with 4,207 adolescents (2006), 6,264 adolescents (2011) and 6,026 adolescents (2016). Logistic regression was used to evaluate the secular trend of suicidal ideation. Multilevel logistic regressions evaluated the factors associated with suicidal ideation in the survey conducted in 2016. Results: There was a positive trend in suicidal ideation prevalence in 2016 compared to the prevalence in 2006 and 2011, in both boys and girls. Low social support, poor sleep quality, and low parental supervision were associated with suicidal ideation in boys and girls. Exposure to violence and bullying was associated with suicidal ideation only in girls. TV time and computer and videogame time were not associated with suicidal ideation in boys or girls. Conclusion: There is an alarming trend of increased suicidal ideation in adolescents. Several dimensions were associated with suicidal ideation in adolescents, especially social support, sleep quality, and parental supervision.