Hematopoietic growth factors stimulate proliferation and enhance functional activity of hematopoietic cells. Erythropoietin, recombinant human (rh) granulocyte colony stimulating factor (CSF), rh granulocyte macrophage CSF and rh interferon have been proven to be a clinically useful therapy. Several other cytokines with other unique effects are being developed for possible clinical usage. The purpose of this manuscript is to review novel uses of current approved cytokines and potential application of experimental growth factors.