Erythropoietin level was studied in blood plasma of humans from different age groups and in patients with chronic hearts failure of ishemic genesis. It was determined that there was no statistically significant difference of erythropoietin level among the age groups. Erythropoietin level in patients with chronic heart failure was 16-fold greater (102.86 +/- 29.04 mU/ml) than in the studied elder aged groups (6.38 +/- 1.82 mU/ml). The data obtained indicate that elderly (60 to 85 years) persons' organisms retain the ability of response to hypoxia by intensive erythropoietin production.