In order to evaluate the possibility of intrafamilial transmission of the human immunodeficiency virus (HIV), a serological follow up of 104 household family members of HIV seropositive subjects with whom they were not having sexual contacts (SC) was carried out. The coexistence of other risk factors in the studied subjects was excluded. Of the initial seropositive patients (SP), 87.5% showed clinical and immunological alterations that could be attributed to the HIV infection. 32.6% of the SC lived in poor sanitary conditions with their respective SP. 3.8% of the SC shared toothbrushes with the group 29.8% shared shaving blades and 81.7% shared combs o hair brushes. After a 12.35 +/- 5.42 month follow up, none of the SC seroconverted. The results obtained suggest that the possibility of HIV transmission to household family members of HIV infected subjects is extremely unlikely if not impossible.