This review compares the efficacy and adverse effects of specific erythropoietic stimulants (i.e., epoetin [alfa or beta], darbepoetin alfa) when used to manage anemia in patients undergoing cancer therapy (i.e., chemotherapy and/or radiation). This review also addresses questions relevant to optimizing the use of erythropoietic stimulants as a general class: the outcomes of using alternative thresholds to initiate or discontinue treatment and whether there are early predictors of response to treatment.