Multiple myeloma is one of the 20 most frequent malignancies in Germany. Initial symptoms are usually non-specific. Assessment of bone marrow and laboratory data as well as imaging techniques are essential for diagnosis and prognostic evaluation. Data from molecular cytogenetics have led to a better understanding of the pathogenesis of multiple myeloma. Cytostatic therapy with alcylating agents and glucocorticoids prolongs the survival. High-dose therapy followed by transplantation of autologous hematopoietic stem cells improves prognosis for patients up to the age of 70. Currently, modifications of allogeneic hematopoietic stem cell transplantation, anti-angiogeneic and immunomodulatory drugs as well as proteasome inhibitors are evaluated in clinical trials. Supportive care has derived benefit from the introduction of new bisphosphonates.