Aim. The aim of this investigation was to determine temporal and histological distribution of the expression of bone morphogenetic proteins 2, 4 and 7, and their inhibitors (gremlin, noggin, chordin and follistatin) during normal, induced (ectopically), and pathological osteogenesis. Material and methods. The investigation was conducted on human and animal material. Twenty samples of osteophytes and associated parts of the synovial membrane of the knee joint were obtained from 20 patients who underwent artificial joint implant surgery (total knee endoprosthesis) at the Orthopedic clinic in Lovran. Twenty samples of normal articular cartilage with associated subchondral bone and the synovial membrane of the joint capsule were taken from the knee joint of deceased persons following autopsy at the Institute of forensic medicine and crime investigation at the Faculty of Medicine in Rijeka. The samples were harvested from knee joints without macroscopic signs of degenerative and inflammatory changes. The investigation on the animal material included 150 female Hannover – Wistar rats, 3 months of age and 300 g of weight. The animals were implanted demineralized bone matrix subcutaneously at bilateral ectopic place in the chest region. Protein expression and localization was determined by immunohistochemical analysis and Western blot. Results. The expression of bone morphogenetic proteins 2, 4 and 7 varied during developmental phases of ectopic osteogenesis. In the early phase of osteogenesis, BMP-2 and BMP-4 were significantly expressed, whereas during the late phase, the expression of BMP-7 increased. Inhibitors of bone morphogenetic protein (noggin, chordin, gremlin i follistatin) were co-expressed with the studied BMP during all phases of osteogenesis. The level of expression of specific inhibitors in the connective membrane of the implant was constant during the whole process of ectopic osteogenesis, although the expression levels between inhibitors varied. In chondrocytes in the osteophytes, BMP-7 was more expressed than BMP-4, while BMP-2 was not expressed. BMP inhibitors in chondrocytes of the osteophytes were co-expressed with BMP. The expression of BMP and their inhibitors in the cells of bone tissue osteophytes was minimal. Conclusion. During different processes of osteogenesis (physiological, pathological, ectopic) the expression patterns of bone morphogenetic proteins and their inhibitors in cartilage and bone tissue were specific and markedly different. Complex local interaction of these proteins is always directed to the establishment and maintenance of local homeostasis of bone tissue. Besides local interaction, BMP and their inhibitors, and the cells whose activity they affect depend on systemic factors (e.g. hormones). In other words, although the studied proteins – BMP and their inhibitors exhibit immediate antagonistic activity, as a whole, their role is synergistic and involved in the homeostasis of bone tissue, i.e. the skeletal system and, thus, the organism as a whole.