In order for the mineral levels in the body to be accurately determined, it is essential to determine the mineral content of bones together with that of blood serum. In this study, blood serum and bone samples were collected from cattle in and around the provinces of Istanbul, Tekirdag, Kirklareli and Edirne and it was attempted to determine reference values. In each region, blood and bone samples were collected from 100 heads of cattle and Phosphorus. (P), Calcium (Ca) and Magnesium (Mg) proportions were calculated. According to the results, it was found that the levels of P, Ca and Mg in bone samples of the cattle in Northwest of Turkey were 132.76 +/- 17.84, 333.23 +/- 163.02 and 2.38 +/- 0.32 mg g(-1), respectively, while mineral levels in blood serum were 7.88 +/- 1.05, 10.80 +/- 0.71 and 2.37 +/- 0.68 mg dL(-1), in the same order. It was thought that these values might constitute a reference point for serial measurements that would be made for keeping the cattle in our region under control against metabolic diseases.