Copper (Cu), Zinc (Zn), and Magnesium (Mg) are essential trace elements for health and show variations in disease states. Reference values for these have been determined. However, reference values for the population in Southern Turkey, has not been determined. Thus the aim of this study was to determine the reference values for Zn, Cu and Mg in plasma and Zn and Mg in erythrocytes. Blood was taken into EDTA. Atomic Absorption Spectrophotometry was used for analysis of plasma and erythrocytes. A total of 2067 samples were analyzed for plasma and erythrocytes. A total of 2067 samples analyzed for plasma Cu, Zn, Mge were; 15.89±2.20. µmol/L, 13.92±2.60 µmol/L, 859.65±102.82 µmol/L, respectively. Erythrocyte Zne - and Mge - were 4.59±2.29 µmol/gHb and 7.36±2.67 mmol/gHb in a total of 1861 persons. There was no statistically significant difference between the sexes but there was statistically significant difference in different age groups.