Girls’ poor ability to manage menstrual health (MH) imposes barriers to education and general wellbeing, especially in low- and middle-income countries. This paper presents the results of the Ritu trial, a 2-year clustered randomized controlled trial, examining the effect of a multi-faceted menstrual health intervention in Bangladesh. We randomized 148 schools from one rural district, into one of three groups; i) receiving a school program (sanitation facilities, MH education and support); ii) a school program and a targeted household program (parental MH education); iii) or the control group. The primary beneficiaries are schoolgirls in grades 6 until 8, age 11-15. We measure short- to medium-term impacts on school attendance, a set of psychosocial outcomes, and menstrual health outcomes. We use three sources of school attendance data: information from administrative records; self-reported survey responses and data from spot-checks where someone from the research team would appear unannounced and on randomly selected dates at school to record attendance. We find significant treatment effects in both treatment arms. The Ritu trial significantly improved menstrual health outcomes. Moreover, it significantly reduced school absence rates and reduced the likelihood of dropping out of school before grade 8. The program also improved psychosocial wellbeing and empowerment during menses, but this did not translate into substantial improvement of general wellbeing and empowerment. We find little evidence that the additional household program generated larger effects than the school program alone – which is important for programming purposes given the substantial additional costs of the household intervention. Our findings show the school program was considerably more cost-effective than the combined program, both when measured in ‘additional years of schooling’ and ‘learning-adjusted years of schooling’. Even though MH programs are becoming more prevalent, supporting quantitative evidence on their impact is very limited. We show a positive impact of a menstrual health program on school attendance and other psychosocial outcomes of adolescent girls.