Abstract : When acute arthralgia is associated with focal osteoporosis and reversible epiphyseal edema, all three spontaneously resolving without sequelae in a few months, it is then called transient focal osteoporosis. Well known at the hip, this pathology may be expressed at other joints and have a migratory character. In this case report, the patient presented himself with migrating transient focal osteoporosis that successively undertook, over one year, various anatomical zones within the same knee and then reached the contralateral knee. The evolution was characterized by a healing without sequelae after discharge and analgesic treatment.