Abstract: Extramedullary multiple myeloma (EMM) responds poorly to conventional treatment strategies, resulting in dismal outcomes. Thus, the de novo identification of EMM patients with a poor prognosis and the choice of more precise treatment options are important. Here, we present an overview of the impact of factors associated with EMM prognosis, including the type of extramedullary disease, the location and number of extramedullary lesions, the disease staging system, hematological counts and biochemical parameter analysis results, abnormal cytogenetics, and tumor cell burden. Furthermore, we also summarize recent advances in the treatment of EMM involving target drugs and immune cell therapy.