Determination of the number of platelets in HIV-infected people who applied in the Samara Regional Center for Prevention and Control of AIDS and infectious diseases. Thrombocytopenia was detected in 79%, severe in 23,1%. It was recorded at any stage of HIV infection and correlated with the level of CD4 lymphocytes. 45 patients was performed sternal puncture. Morphological evaluation of bone marrow showed changes in 87% of HIV-infected The most common violation was the low content or absence of megakaryocytes in bone marrow (72,5%).