Although adolescents' sexual health is generally better when parents and adolescents communicate about sex and sexuality, researchers have found parents can be reluctant to engage adolescents in conversations about those topics. To better understand why, we reviewed prior literature and identified four types of parent-based barriers to communication with adolescents about sex: limited sexual health knowledge, believing adolescents are not ready to discuss sex, discomfort discussing sex, and demographic factors. We then used the Theory of Planned Behavior to develop recommendations for how health educators can address these barriers, thereby increasing parent-adolescent sexual health communication.