Globin synthesis rate (GSR) by nucleated erythroid cells was investigated in 40 patients suffering from chronic glomerulonephritis, in 24 subjects with other renal diseases and in 8 healthy controls. GSR was reduced in nephrogenic anemia; moreover, this reduction took place in a few patients without anemia. The correlation between GSR and some characteristics of erythropoiesis was examined. The supression of GSR is probably one of the important causes of nephrogenic anemia.