Materials and Methods: This cross-sectional study was conducted on 1017 female students who were studying at second and third grade of secondary schools in Tabriz, 2013. Samples were selected randomly. Questionnaires used in the study were the practice and socio-demographic questionnaires. General linear model was used to determine predictors of practice.

Results: Mean (SD) of practice score in adolescent girls was 64.2 (12.1) from attainable score of 0-100. More than half of students (56.7%) had moderate practice. According to adjusted general liner model, variables of being in second class, having a father with elementary education or illiterate, living in undesirable economic status, having peer groups and friends as main source of information, having insufficient information about puberty had negative relationships with practice score. While, there was a positive relationship between age at menarche and practice score (p<0.05).

Conclusion: The findings show that the practice of adolescents about puberty and menstrual hygiene is moderate. Thus, it is necessary to educate the girls about puberty and menstrual hygiene to enable them to have a healthy reproductive life in future.