Histological lesions occurring in the placenta of human immunodeficiency virus positive women are rare and non specific and opportunistic infections are exceptional. We report the case of a female intravenous drug abuser with AIDS, who had an abortion associated with fever. Histological, immunohistochemical and ultrastructural studies of the placenta allowed the diagnosis of toxoplasmic infection. In comparison of the high frequency of toxoplasmic lesions seen in different organs, we did not find any case in the literature of placenta toxoplasmosis in AIDS.