Menstruation is a normal biological process experienced by more than 300million women globally every day. Women require clean menstrual absorbents that can be changed as often as needed in a private and safe place with proper hygiene and disposal facilities. These needs must be met consistently throughout the duration of the menstrual cycle. Access to menstrual needs is crucial for women's health, wellbeing, and dignity. This study assessed the prevalence and factors associated with unmet need for menstrual hygiene management (MHM) in Ethiopia, Kenya, Uganda, Burkina Faso, Ghana, and Niger. We used data from the Performance Monitoring for Action (PMA) 2020surveys. We defined the unmet need for MHM as the"lackof resources, facilities and supplies for MHM." Sample characteristics were summarised using frequencies and percentages, while prevalence was summarised using proportions and their respective confidence intervals (CI). Factors associated with unmet need for MHM were assessed using multilevel logistic regression models. The study included 18,048 women of reproductive age from the six countries. The prevalence of unmet need for MHM was highest in Burkina Faso (74.8%), followed by Ethiopia (69.9%), Uganda (65.2%), Niger (57.8%), Kenya (53.5%), and lowest in Ghana (34.2%). Unmet need for MHM was consistently higher among uneducated and multiparous women, those who reused MHM materials, practiced open defecation, and lived in rural areas across all six countries. The odds of unmet need for MHM were higher among younger women under 35 years, unmarried women, those with lower education levels, and those from poorer households. Similarly, the reuse of MHM materials, use of shared or non-improved toilet facilities, and open defecation increased the odds of unmet need for MHM. In contrast, the presence of handwashing facilities reduced the odds of unmet need for MHM. More than half of the women in five of the six countries have an unmet need for MHM, with significantly higher odds among younger women, those with low wealth status, the unmarried, and those with inadequate access to sanitary facilities. This study highlights the state of period poverty in Sub-Saharan Africa. Efforts to end period poverty should consider MHM needs as an integrated whole, as addressing each need in isolation is insufficient.