ObjectivesTo assess the impact of a school-based menstrual education programme on: (1) menstrual knowledge, beliefs and practices, (2) menstrual disorders experienced, and (3) restrictions on menstruating adolescents.DesignIntervention study.SettingAraihazar area, Bangladesh.Participants416 adolescent female students aged 11–16 years, in grade 6–8, and living with their parents.InterventionsA school-based health education study conducted from April 2012 to April 2013.Primary and secondary outcome measuresWe randomly selected 3 of 26 high schools in the study area. We delivered 6 months of educational intervention by trained (by an obstetrician and gynaecologist) research assistants (RAs) on menstrual hygiene among school girls. RAs read the questionnaire and participants answered. The changes in knowledge, beliefs and practices regarding menstruation, menstrual disorders experienced, and the restrictions and behaviours practiced by menstruating adolescents were compared between the baseline and the follow-up assessments.ResultsAfter health education, participants reported a significant improvement (p<0.001) in ‘high knowledge and beliefs’ scores compared to baseline (51% vs 82.4%). Significant improvement was also observed in overall good menstrual practices (28.8% vs 88.9%), including improvements in using sanitary pads (22.4% change after the intervention), frequency of changing pads/cloths per day (68.8%), drying the used absorbent (77.6%), methods of disposing of the used absorbent (25.5%), and cleaning of genitalia (19.2%). During the follow-up, the participants reported significant improvements in the regularity of their menstrual cycle (94.5% vs 99.5%) and fewer complications during menstruation (78.6% vs 59.6%).ConclusionsThe programme produced significant changes in the knowledge, beliefs and practices of menstrual hygiene, complications from lack of hygiene, and the behaviour and restrictions of the menstruating adolescents. These results demonstrate the feasibility of implementing a health education programme for adolescents on menstrual hygiene in secondary schools serving rural Bangladesh.