This paper explores menstruation as a domain of kinship within and across three generations of women in central Kerala, India. Based on fieldwork, it shows that certain gendered practices of intimacy and care work in the context of menstruation produce kinship bonds among them, which the authors enunciate as ‘menstrual kinship.’ In the past, it was shared chiefly among consanguineal and affinal kinswomen and same-caste women, and became conspicuous only during public menarche rites and the separation of menstruating women. Presently, menstrual kinship extends to women outside the natal and marital family, often overturns the traditional perspectives of menstruation and actively contributes to maintaining the contemporary ‘invisibility’ of menstrual phenomena. The paper posits that regardless of its gendered nature and time-tethered transformations, ‘menstrual kinship’ has always existed as a realm that can release menstruation from conventional discourses of patriarchy and caste and aid in retrieving women’s phenomenological experiences and voices. © 2022 Informa UK Limited, trading as Taylor & Francis Group.