In many sub-Saharan African communities, caring for vulnerable children in the era of HIV/AIDS appears to be creating deep financial, physical and psychological strains for care-givers, the great majority of whom are ageing women or ‘grandmothers’. Yet, limited primary research has been carried out with older women in specific communities, and therefore grandmothers' collective responses, sources of support, complex lived experiences, and diverse family situations are not well understood. This paper presents the findings of research undertaken in four communities in KwaZulu-Natal, South Africa, between 2006 and 2010. The purpose was to understand the daily stresses, collective responses and mobilisations of older women in these communities. The research involved repeated focus groups, interviews and participant observation involving approximately 100 older women. In the analysis, attention is given to the diversities among participants, the ways in which HIV/AIDS intermingles with other stresses in their lives to drive their mobilisations, and their collective responses, even amidst highly constrained conditions. Through these lenses, the paper illuminates how older women in these communities are organising in response to the combined, devastating and diverse effects of HIV/AIDS, poverty, violence and illness. It also suggests that, counter to some stereotyping of ‘African grandmothers’ as frail or passive, these women are forming associations in order to generate incomes, resist stigma, connect with broader support networks and provide care to hundreds in their communities.