The authors used state-of-the-art concept mapping approaches to examine structural institutional effects of church and secular high schools on the types of sexual and HIV-prevention education messages transmitted to learners in Zimbabwe. Participants were school teachers (n = 26), school counselors (n = 28), and pastors involved in student pastoral care (n = 14; males = 27, females = 41). They reported on messages perceived to influence sexual decisions of learners in their school setting. The self-report data were clustered into message types using concept mapping and contrasted for consistency of content and structure both between and within type of school. The authors also engaged in curriculum document study with member checks in the participant schools to determine convergence of the evidence on school-type effects of the messages transmitted to students. Church schools prioritized faith-informed sexual and HIV-prevention messages, whereas both types of schools prioritized Life skills education and a future focus. Secular schools prioritized sex and HIV messages in the context of community norms. Facts about HIV and AIDS were relatively underemphasized by church schools. The implicit knowledge values that differentiate types of schools influence learner access to information important for their sexual decisions.