This study was conducted to determine the effects of different levels and sources of copper supplementation on hematological values, ceruloplasmin and plasma copper, zinc and iron status in Mehraban male lambs. Twenty growing lambs were randomly allotted to four different treatments. Treatments consisted of 1) 10 mg/kg Cu in the form of CuSO4, 2) 20 mg/kg Cu in the form of CuSO4, 3) 10 mg/kg Cu in the form of Cu-Proteinate and 4) 20 mg/kg Cu in the form of Cu-Proteinate, administered daily with the basal diet. Blood samples were taken via the jugular vein on days 0, 7, 14, 28, 57 and 65 then analyzed for hematological parameters. The samples taken on days 28 and 65 were also used for a determination of serum ceruloplsmin activity as well as plasma Cu, Zn and Fe concentrations. There was a significant (P < 0.001) negative correlation observed between plasma Cu and Fe (r = -0.604), and as plasma Cu increased (up to d 65) plasma Fe concentrations decreased in all the treatments. Copper source exerted a signi?cant effect on ceruloplasmin concentration (P < 0.05). on d65, the 20ppm Cu-proteinate treatment carried the highest ceruloplasmin concentration (P < 0.05). Copper level exerted a significant effect on RBC, PCV and Hb, with the treatment of 20 ppm level causing higher values (P < 0.05). No clinical or hematological signs of copper toxicity were observed throghout the study. There was an evidence of adverse effects of high Cu supplementation on RBC count, PCV and Hb at the conclusion of the experiment. It can be concluded that the obtained result may be due to Cu interaction with iron as well as its effect on iron metabolism and hematopoesis.