With aging, many people develop Alzheimer's disease or related dementias (ADRD) as well as chronic physical health problems. The consequent care needs can be complicated, with heavy demands on families, households and communities, especially in resource-constrained settings with limited formal care services. However, research on ADRD caregiving is largely limited to primary caregivers and high-income countries. Our objectives are to analyse in a rural setting in South Africa: (1) how extended households provide care to people with ADRD; and (2) how the health and wellbeing of all caregivers are affected by care roles. The study will take place at the Agincourt health and socio-demographic surveillance system site of the MRC/Wits Rural Public Health and Health Transitions Research Unit in Mpumalanga Province, northeast South Africa. We will recruit 100 index individuals predicted to currently have ADRD or cognitive impairment using data from a recent dementia survey. Quantitative surveys will be conducted with each index person's nominated primary caregiver, all other household members aged over 12, and caregiving non-resident kin and non-kin to determine how care and health are patterned across household networks. Qualitative data will be generated through participant observation and in-depth interviews with caregivers, select community health workers and key informants. Combining epidemiological, demographic and anthropological methods, we will build a rich picture of households of people with ADRD, focused on caregiving demands and capacity, and of caregiving's effects on health. Our goal is to identify ways to mitigate the negative impacts of long-term informal caregiving for ADRD when formal supports are largely absent. We expect our findings to inform the development of locally relevant and community-oriented interventions to improve the health of caregivers and recipients, with implications for other resource-constrained settings in both higher- and lower-income countries.