Morphohistochemistry of the placentas at HIV-infection has been studied. Numerous hemodynamic, involutive, distrophical and not so much expressed compensative, adaptive processes, malfunctions of the placental metabolism were observed, which led to development of the secondary chronic relative insufficiency of the placenta in all cases. Above mentioned pathological processes in some cases combined with inflamatory injures of placenta’s tissues, which totally had a negative influence on fetus’ condition.