Research using retrospective or cross-sectional data suggests that suicidal ideation rates peak during mid-adolescence. This study used a longitudinal, community sample of adolescents who reported suicidal ideation repeatedly over 7 years to examine suicidal ideation trends. We hypothesized that a mid-adolescence peak in ideation is limited to adolescents exposed to friends' or family members' suicidality. Ideation trends were compared across groups exposed and not exposed to others' suicidality and statistically assessed using growth curve analyses. Overall, ideation rates peaked at age 15 years. Group comparisons revealed that the peak was limited to adolescents whose parents reported suicidality.