This study examines the role that older-aged parents play in the care and support of adult sons and daughters with HIV or AIDS and of AIDS orphans in Thailand within the context of a limited institutional safety net. The analysis draws on both quantitative and qualitative data from survey and open-ended interviews with the parents and from individual case information provided by key informants. The results show that health and welfare benefits provided to persons with HIV or AIDS in Thailand are significant but that this formal safety net still leaves the bulk of care and support, as well as the fostering of orphans, to the family. Reliance on parents is particularly common, a pattern that likely occurs in other developing countries with serious epidemics. Programs to improve caregiving and to provide support to persons affected by the epidemic need to recognize the crucial role of older-aged parents and to incorporate them in their efforts.