Iron injection in beef calves during the 1st week after birth increased their PCV, hemoglobin (Hb) concentrations, mean corpuscular volumes (MCV), and mean corpuscular Hb (MCH). These increases persisted between weeks 2 and 12. The RBC count during the 1st week after birth had a positive correlation with the PCV and Hb concentrations and a negative correlation with the MCV and MCH. There was a positive correlation between the serum iron concentration of the dams and their MCV and mean corpuscular Hb concentration. There was also a positive correlation between the MCV and MCH of the dam and their calf's MCH. Seemingly, iron injection did not affect weight gain during the first 18 weeks of life.