Abstract: Results from a randomized experiment conducted with teenage schoolgirls in Cameroon suggest that HIV prevention interventions can be effective at reducing the incidence of teen pregnancy in the following 9-12 months by over 25 percent. We find little difference in effectiveness between one-time, one-hour sessions delivered directly to students by specialized consultants and sessions delivered through regular school staff trained over two days by specialized consultants. We also find little difference between the standard “Abstain, Be Faithful, Use Condoms” curriculum and an enriched curriculum that includes information on the heightened risk of cross-generational sex. Lastly, a one-time, one-hour self-administered questionnaire on HIV and sexual behavior has an equally large impact on teen pregnancy. These results suggest that rural teenage schoolgirls’ sexual behavior is highly responsive to even small interventions that make the risks of HIV and pregnancy salient. 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.