Caregiving by older adults is a common phenomenon, enhanced in the era of HIV infection. This longitudinal study was set up to examine the effect of caregiver age, relationship and mental wellbeing on child (4–13 years) outcomes (psychosocial and cognitive) in a sample of 808 caregiver- child dyads in South Africa and Malawi. Respondents were drawn from consecutive attenders at Community Based Organisations (CBOs) and interviewed with standardised inventories at baseline and followed up 12–15 months later. Analysis focused on three separate aspects of the caregiver; age, relationship to the child, and mental wellbeing, results are stratified with regard to these factors. Results showed that compared to younger caregivers, over 50 years were carrying a heavy load of childcare, but caregiver age for the most part was not associated with child outcomes. Being biologically related to the child (such as biological grandparenting) was also not a significant factor in child outcomes measured. However, irrespective of age and relationship, caregiver mental health was associated with differences in child outcome – those children of caregivers with a greater mental health burden were found to report experiencing more physical and psychologically violent discipline. Over time, the use of violent discipline was found to reduce. These data suggest that older caregivers and grandparents are providing comparable care to younger caregivers, for young children in the face of the HIV epidemic and that interventions should focus on mental health support for all caregivers, irrespective of age or relationship to the child.