In comorbidity of chronic obstructive pulmonary disease and urolithiasis with oxalic acid stones changes of erythropoiesis were found in 78,3 % of patients, in particular – 52,2 % corresponded to mild iron-deficiency anemia and in 26,1 % of patients – chronic disease anemia or their combination. These changes were accompanied by likely reduction of blood erythropoietin within 2,9-3,5 times less (p<0,05)