Menstrual Health and Hygiene (MHH) is an essential component of individual and population-level health and is inextricably linked to the environment. Few scholars have explored women's day-to-day experiences of managing their monthly period within the unique environment of informal settlements. We used data from in-depth interviews with women 18–55 years in Mathare informal settlement in Nairobi, Kenya. Findings suggest that aspects of the social environment, particularly menstrual stigma and social and gender inequities, combined with resource limitations, such as lack of water, sanitation, disposal facilities, and waste management influence menstrual management, and this, in turn, impacts the physical environment.