Abstract: The effects of zinc supplementation on growth and serum parameters were investigated in Ross PM3 broiler chicks. 60 day old chicks were assigned to four treatments of 0, 20, 40, 80 ppm supplemental zinc. Blood from wing vein was analyzed for serum glucose, cholesterol, enzymes and minerals. Zinc supplementation had no significant effect on live weight and 80 ppm zinc lowered the serum glucose concentrations. Cholesterol levels slightly decreased in zinc supplemented groups. Serum alanine aminotrasferase activity remained unchanged but aspartate aminotransferase activity was increased and alkaline phosphatase activity was decreased in zinc supplemented chicks. Gamma-glutamyltranspeptidase activity was also decreased in all supplemented groups. Significant reductions occurred in serum calcium, magnesium and inorganic phosphorus levels. None of the supplemental zinc levels had significant effect on iron and copper concentrations.