Few references of maternal AIDS associated to Toxoplasma gondii infection exist in the literature, in spite of the fact that the newborns of HIV infected mothers are prone to infection. We present a case of a 23-year-old HIV positive mother with accentuated weight loss and Kaposi's sarcoma during pregnancy, having probably been infected by toxoplasma in the last trimester. The newborn showed early and progressive respiratory distress, disseminated petechiae and hepatosplenomegaly. He died eight days after birth. Morphological feto-placentary examination revealed acute, severe and disseminated toxoplasma lesions; noteworthy was the abundance of trophozoites and cysts of the protozoon. HIV p24 antigen was detected in the placentary tissues by immunohitochemistry.