The erythropoietin receptor (EpoR) and erythropoietin (Epo) mediate erythropoietin-induced erythroblast proliferation, differentiation and survival. This study examined the effects of the expression of EpoR on K562 (erythroleukemia) cells upon normoxia and hypoxia. In addition, the impact of the combined effect of recombinant human Epo and hypoxia was investigated. K562 (erythroleukemia) cells and as control group HL60 (promyeloblast) cells were cultured Hypoxic incubation was performed with 5% O(2), 5% CO(2) and balance Nitrogen for 24 hours. After 24 hours, K562 and HL60 cells were transferred to normoxic and 5% hypoxic conditions. Recombinant Erythropoietin-alpha was added (10 U/ml) to the cells at the beginning of the experiment. Cultured cells were subjected to viability analysis, total RNA isolation, and protein isolation at three timepoints: 3 h, 6 h, and 24 h. Viability was analysed with a trypan blue exclusion using the Vi-Cell automated cell viability system. RT-PCR and western blot results of normoxic and hypoxic K562 and HL60 cell lines with/without rhEPO were compared.