Background: Poor menstrual health can lead to serious health problems among adolescent girls. This study was performed to assess the impact of two school-based menstrual education programs (lecture and peer) on menstrual knowledge and practices in high school girls.

  Methods: This quasi-experimental interventional study was conducted on 200 female students (100 in peer and 100 in lecture group) of a high school selected by cluster sampling in Hamadan city in 2014. The participants were trained either by peers or through lectures during 4 weekly sessions and then were compared. Data were collected by a structured questionnaire containing questions about students' menstrual hygiene, knowledge and practice. Two groups were compared at pre-test, immediately after training, and one month after completing the training program. Data were analyzed using descriptive statistics, independent t-test, chi-square test and analysis of variance with repeated measures.

  Result: There were no significant differences between the two groups for mean age (13.35 in lecture and 13.31 in peer group P> 0 .05) and age at menarche (12.41 in lecture and 12.20 in peer group P> 0 .05).The mean score of knowledge and practice in the two groups significantly increased over time (before, immediately after and one month after training) (P< 0 .001). The results showed a significant difference between the two groups on knowledge and practices of menstrual health (P< 0 .001).

  Conclusions: Peer group education is an efficient method for menstrual health promotion. Hence, health planners must be able to provide health programs for training and empowerment of adolescent girls.