In order to evaluate the presence of HTLV-II infection in a cohort of newborns born from HIV-1 infected mothers, a retrospective study was conducted on 80 newborns. Only 1 birth serum sample (1.25%) was found seropositive for HTLV-II by Western Blot suggesting a transplacental transmission of anti-HTLV-II antibodies. Two consecutive PCR performed on PBMCs of the seropositive newborn resulted negative suggest the absence of the infection. More extensive studies are needed to assess the risk of transmission in areas with a higher prevalence of HTLV-II infection.