In South Africa, older people have become the primary caregivers of children and grandchildren infected or affected by HIV and AIDS. This study explores the determinants of the perceived ability to care for children and grandchildren in the domains of providing nursing care, communicating with (grand) children, generating income and to relax. Structured one-on-one interviews were conducted among 409 isiXhosa speaking older people in two sites in the Eastern Cape Province of South Africa. Results showed that perceived ability among older people to provide nursing care was primarily dependent on the level of knowledge on accessing grants and personal norm towards providing care. Perceived ability to communicate effectively with children and grandchildren was most strongly predicted by a positive attitude towards communication and perceived ability to provide income was influenced by a more negative attitude towards people living with HIV or AIDS. Perceived ability to relax was dependent on more negative attitudes towards communication, lower perceived responsibility to provide income and a higher perceived behaviour control over providing nursing care. The findings of this study add relevant information to understanding the psychosocial context in which older people provide HIV and AIDS related care and support the development of targeted programmes to assist older people in their role as caregiver.