20 enzymatic activities and the glutathione content of newborn erythrocytes are compared (a) to normal and (b) to comparably reticulocyte-rich nonneonatal red cells. Six were very high in comparison to either control group (GSH, PGK, Enol., G-3-PD, GPI, G-6-PD). Five were very low (ACHE, RPK, GSH-Px, AK and PFK). The mean of the remainder differed from the mean of comparably reticulocyte-rich blood by less than 1 SD of the latter mean. Cord erythrocytes exhibit a characteristic metabolic pattern not explained by a young mean cell age alone.