The study explored the level of serum erythropoietin in patients with intermediate beta-thalassemia to determine possible correlations with hemoglobin level and fetal hemoglobin level and other parameters. The sampling consisted of 58 examined patients with intermediate beta-thalassemia. The contrl group consisted of 30 healthy persons. All patients underwent the identification of erythrocytes count, hemoglobin level, hematocrit indicator, erythrocyte indices (MCV, MCH, MCHC), fetal hemoglobin level, hemoglobin A2 level. Also, to all patients the identification of serum erythropoietin and ferritin levels was applied The presence/absence of relationship between these indicators was established using the correlation coefficient calculation. The study results demonstrated that under intermediate beta-thalassemia are observed statistically valid decrease of level of hemoglobin and erythrocytes, increase of percentage of fetal hemoglobin, hemoglobin A2 ferritin and serum erythropoietin as compared with standard values. The analysis of correlation relationships between indicators under study revealed that under the intermediate beta-thalassemia in many cases the failure of interdependencies of indicators marked as normal are established. The presence of clear-cut inverse interrelationship between serum erythropoietin level and hemoglobin level has to be taken into account in the process of treatment of this disease with medications of recombinant erythropoietin.