Thailand has been severely affected by AIDS/HIV. The epidemic has undermined the health of the population of working age, placing stress on intergenerational relations and threatening the social fabric. Older people in families affected by the disease, although not the main victims, have experienced major changes in relationships with their adult children and grandchildren. However, the availability of antiretrovirals has transformed HIV infection from a lethal to a chronic disease. Intergenerational relationships are analysed with data from a quantitative survey of HIV-infected adults currently receiving antiretroviral treatment in Northern Thailand. The introduction of antiretroviral treatment has eased the pressure on families. Where HIV-infected adults are more dependent on their older parents, it is because they are single and childless or single parents. While ageing parents remain a source of support for their adult children, the introduction of antiretroviral treatment has radically changed the prospects for HIV-infected adults and their regained health allows them to work, take care of their family and fulfil their filial duties as expected in Thai society. If Thailand's original aim in introducing health policies in this area was to curtail the HIV epidemic, its positive impact on intergenerational relations is an additional benefit.