A seroepidemiological survey conducted from January to May 1986 among 650 pregnant women from mixed rural/urban origin in the Moungo district, Cameroon, revealed a very low prevalence of antibodies to human immunodeficiency viruses (HIV). One subject appeared to be infected with HIV 2. This is remarkable since HIV 2 has been isolated predominantly from West-African subjects. Further epidemiological and antropological studies are required to explain the distribution of HIV 1 and HIV 2 throughout the African continent.