Multiple myeloma (MM) is a systemic malignancy of pathologic plasma cells that is treatable with various chemotherapeutic agents and irradiation, but rarely curable. The mean age of affected patients is the mid-60s. Since the clinical presentation of multiple myeloma varies from asymptomatic to aggressive progression, there are many therapeutic options, such as follow-up without any treatment, and high-dose chemotherapy with stem cell transplantation. Recent advances in disease biology and implications for therapy are reviewed and summarized.