Tertiary hyperparathyroidism (HPT) is a rare condition that affects patients with secondary HPT, which develop hyperplasia of the parathyroid glands, thus causing an increase in parathyroid hormone levels. Bone alterations are the main consequences of this condition including the development of osteolytic lesions called brown tumor. This article reports an unusual case of brown tumors located in the maxilla and mandible in a 19-year-old man with chronic renal failure with hyperplasia of the parathyroid glands. The lesions regressed approximately 5 months after the parathyroidectomy. At this same time, the patient underwent renal transplant. The patient was followed for 5 years, showing improvement in overall clinical status. There was also improvement of the results of laboratory tests and the pattern of trabecular bone. The correct diagnosis of oral lesions was of great relevance for the conservative treatment could have been chosen.