This article describes the processes of self-care practiced by people of a very old age in rural localities in southern Chile. Self-care, in this case, is also a response to a wider context of the provision of home care for the elderly. Using a qualitative approach, we implemented an ethnographic strategy to study the experiences of aging and longevity. This approach allowed us to obtain data from the long-lived individuals themselves and their families, in their own words, and their observable behavior and interactions in family, social and institutional contexts. The present article aims to understand how the phenomenon of self-care is shaped in rural areas in order to deal with illness in subjects aged 90 or more. The results show that the transformations of family structures resulting from the social and demographic changes of the last decades; the relationship that long-lived people and their caregivers establish with health institutions, and the biographical trajectories of medicalization of these subjects are important factors in shaping the nature of self-care in the context of longevity in rural areas. The reality of both the family and the relevant institutions combine to play a role in processes of health/illness/care through the shaping of self-care. Examining illnesses long-lived persons suffer from allowed us to gain insights into the personal, social and collective dimensions of self-care and the provision of healthcare at that stage of life.