We report a 25 years old woman with a four years history of end stage renal disease on hemodialysis. During the last two years of follow up, multiple tender nodules appeared in the left clavicle and ribs. These were diagnosed as brown tumors, secondary to osteitis fibrosa cystica, in the context of a secondary hyperparathyroidism. A subtotal parathyroidectomy was performed and a homologous parathyroid implant was done in the right forearm. The pathological study of the surgical pieces confirmed the presence of the brown tumors and parathyroid hyperplasia. Nine months after surgery, parathormone levels and brown tumor calcifications decreased significantly and bone mineral density increased by 20%. (Rev Méd Chile 2003; 131: 1183-87) .