The authors review contemporary findings on the role of different components of the cytokine network from the aspect of development, prognosis and treatment of multiple myeloma. Greatest attention was devoted to the main growth factor of myeloma elements IL-6, but also to the real or so far sparsely elucidated role of other cytokines (IL-1, IL-2, GM-CSF, G-CSF, IL-3, IL-4, IL-5, IL-10, TNF, interferon alpha and gamma) under conditions in vitro and in vivo. For completeness sake the authors did not omit the problem of the soluble receptor of IL-2 and the role of TNF, TNF beta and in particular IL-1 beta in the pathogenesis of osteolytic lesions and the potential therapeutic role of antibodies against IL-6 (anti IL-6 mab) and interferon alpha and gamma.