The medical history and laboratory data of two persons who have been in contact with HIV-I positive carrier individuals are reported. The serologic data of successive serum samples collected from these persons were first negative, then positive (including antibodies directed against Gag and Env gene products), and finally negative for presence of anti-HIV-I antibodies. Physical examination and other laboratory data, including absolute number of CD4 lymphocytes/mm3, were within the normal range in these two individuals, who presented a reversal of positive serology for HIV-I.