Thirty-two years ago society knew of a new sexually-transmitted disease spread by a human immunodeficiency virus, which causes alterations in a person’s life as well as in the lives of family members aware of the seropositivity. With the increase in the number of elderly seropositives, this study aims to analyse their family life starting from the disclosure of HIV+ diagnosis. Both the extended and the nuclear families were considered. The research was held at the Clinic of Infectious and Parasitic Diseases of the Federal University of São Paulo - SP. 24 men and 13 women participated - ranging from 60 to 82 years of age. All patients signed the consent forms, answered questions about family relations, self-care, health, illness background and treatment adherence, having submitted two genograms - family of origin and current one -, specifying relatives aware of their HIV status and also informing whom they live with and the status of their relationship. The results show that the established family relationships as well as the style and behaviour of each family member are responsible for the choice of diagnosis disclosure of the HIV infection: three elderly seropositive participants live isolated from their family; for 26 families, this knowledge is restricted to some members, forming a nucleus of trust within the extended family; in eight families, all members know about the seniors living with HIV. Finally, it is clear that family life with HIV seropositivity can affect dynamics both positively and negatively. The positive changes refer to a greater extent of love and care, whereas the negative ones are related to absenteeism and discrimination. Health care is mostly carried out independently, with no family interference, and includes practises of no smoking and no drinking, eating properly and a good treatment adherence; nevertheless, few people practise physical activities.