Brown tumor or parathyroid osteopathy is a kind of bony lesion caused by hyperparathyroidism. It appears as an expansive osteolytic lesion mostly in mandible, ribs, pelvis and femur, but rarely in the upper jaw. Bone resorption is the result of osteoclastic activity due to an increased activity of parathyroid hormone. A 25-years-old male patient was operated on due to clinicaly and radiographicaly obvious maxillary tumor and increased values of parathyroid hormon (PTH - 1 050 ng/l). The level of calcium in blood was normal (Ca 2.34 mEq/L). The patient was dialyzed for years because of the chronic renal failure. Histopathologic analysis confirmed brown tumor, that appeared as bony lesion of secondary hyperparathyroidism due to the chronic renal failure. The operation of the upper jaw had been performed before parathyroidectomy, due to an excessive growth of tumor followed by heavy epistaxes. The subsequent parathyroidectomy was followed by the regression of remaining bony lesions.