Bone marrow edema is a clinical finding that can occur in many different locations in the body and may be associated with different diseases. Osteonecrosis has an important place among these variable causes. Particular attention should be paid to the differential diagnosis in terms of the prognosis, course and consequences of the primary cause and the correct diagnosis should not be avoided in order to prevent possible morbidities. When bone marrow edema is identified, many diseases should be kept in mind, from acute traumatic edema to stress fracture, transient osteoporosis to osteonecrosis, or history of corticosteroid usage to drug addiction. The cause and effect relationship between bone marrow edema and osteonecrosis has been questioned from past to present, and this relationship is still controversial. Patients with bone marrow edema should be followed up closely, osteonecrosis and the other pathologies should be kept in mind, diagnosis should be made with the help of imaging methods, and then a diagnosis-oriented treatment should be applied.