Information on history of suicidal thoughts and behaviors is critical in risk assessment, and multi-informant assessment has been recommended. Despite this, relatively little is known about parent-adolescent agreement regarding adolescent suicidality. To examine the extent and predictors of such agreement, 448 psychiatrically hospitalized adolescents and their parents were administered structured interviews assessing suicidal thoughts, plans, and attempts and completed measures of youth internalizing and externalizing behaviors, perceived family social support, and parental distress and psychopathology. Adolescents reported significantly more suicidal ideation, plans, and attempts than parents. Parental history of depression and adolescent perceived family support were associated with significantly greater agreement about suicidality. History of multiple suicide attempts was associated with greater disagreement about suicidality.