The use of magnetic resonance imaging (MRI) for osteoarthritis made it possible to simultaneously detail the state of cartilage, subchondral bone, menisci, ligaments, and synovial membrane. In some studies, a correlation was found between bone marrow edema (BME) and the intensity of the pain syndrome, the progression of OA and the risk of total knee replacement. In other studies, these data were not confirmed. It has been suggested that BME in OA, leading to debilitating pain, is not associated with trauma and is determined by an increase in extracellular fluid. Analysis of MRI images of 80 patients with 1-3 stages of knee osteoarthritis revealed a statistically significant relationship between the presence of bone marrow edema and the thickness of the cartilage of the femur and tibia, rupture and degradation of the medial menisci, the presence of Baker cysts and thickening of the synovial membrane. No reliable relationship was found with the presence and severity of synovitis. A review of data on the effect of various methods of conservative therapy on bone marrow edema in osteoarthritis is presented. The effect of anti-osteoporotic drugs, prostacyclin, Pentosan polysulfate sodium chondroitin sulfate is considered. Thus, OKM is of interest both in terms of the pathogenesis of OA and as an indicator of the effectiveness of the treatment of OA. Our data demonstrate a high incidence of OKM in the late stages of OA. The effect of pharmacological therapies on OKM requires further study.