Why do teenagers take risks and what can be done about it? Results from a randomized experiment conducted with teenage schoolgirls in Cameroon suggest that risky sexual behavior responds to both risk mitigation information and risk salience. We find that sexual education sessions delivered to students either by specialized consultants over an hour, or through regular school staff over multiple weeks, led to improved health knowledge and decreased teen pregnancy rates in the following 9-12 months. A one-time, one-hour group-administered questionnaire on HIV and sexual behavior had an equally large impact on teen pregnancy without improving knowledge — it instead made the risks more salient and changed subjective beliefs. We find no effects among urban schoolgirls, who are more exposed to information and experience much lower rates of teenage pregnancy under the status quo.