Adolescence is a time of rapid changes, including risk for unwanted pregnancies and sexually transmitted infections. Education may improve understanding and attitudes toward menstruation among adolescents thus increasing their awareness of risks and enabling them to protect themselves accordingly. To investigate effects of education on attitudes, two interventions were compared in 345 12-year-old girls. The new, active intervention given to premenarcheal girls just before menarche resulted in improvements in attitudes toward menstruation compared with standard intervention. Thus, just before menarche girls should be offered education modeled after the active intervention. The education must be concrete and based on multisensory learning.