PURPOSE: Report effects on knowledge of sexual health and gender from an intervention using peer methodology in Nicaragua. DESIGN: A prepost nonequivalent control group design. SETTING: Ciudad Sandino, Managua, Nicaragua. SUBJECTS: A total of 599 girls were surveyed, 60% nonintervened and 40% intervened. INTERVENTION: Peer methodology consisted of (1) meetings in which girls talked and worked with other girls, (2) mothers taking an active role in the peer groups, and/or (3) girls watching the soap opera "Sexto Sentido." MEASURES: Indices measuring changes in sexual knowledge and gender vision. RESULTS: Girls participating in the peer groups were twice as likely to have satisfactory sexual health-related self-esteem as those who did not participate. Eleven percent of the girls achieved satisfactory self-esteem as a result of the (peer groups x mothers) interaction and 15% due to the (peer groups x mothers x "Sexto Sentido") interaction. Girls participating in the peer groups were three times as likely to have satisfactory gender visions; if exposed to all three components, they were almost four times as likely to develop satisfactory gender visions. CONCLUSIONS: Peer methodology, participation of a female family member, and an educational soap opera seem beneficial in promoting sexual health-related knowledge and gender vision in young girls.