The authors' investigations found plasmocytic infiltration of bone marrow and marked resorption of bone tissue in patients with multiple myeloma (MM). Instead of the expected reduction in bone marrow volume the latter slightly increased. MM patients have significantly higher quantity of endosteal stromal cells, accumulations of osteoblastic cellular elements considered as initial osteogenesis. A close correlation was revealed between bone tissue volume, number of erythroid elements in bone marrow and red cell count in peripheral blood. Volume of fatty tissues in MM patients is low. MM patients demonstrate pronounced morphofuctional disturbances in hemopoietic microenvironment of bone marrow.