Brown tumor (BT) is a focal bone lesion of hyperparathyroidism. This leads to microfractures and hemorrhage and the appearance of brown tumors, which are seen most commonly in primary hyperparathyroidism, but cases of brown tumors in patients with secondary hyperparathyroidism due to renal failure were increasingly often reported in the literature. We report three cases of patients undergoing hemodialysis and developing BT. case reports A 41-year-old men with acquired bilateral blindness, hypertension, Marfan syndrom and undergoing hemodialysis since 2007. He had a parathormone (PTH) rate at 1646 pg/ml on2017 with two femoral neck fractures operated on the right side on 2018 and on the left side on 2019. The cervical ultrasonography performed in April 2019 showed hypoechoic nodules, the largest was on the right with irregular contours and having an endothoracic extension coming into contact with the common carotid and arterial brachio-cephalic trunk. A parathyroid computed tomography scan (CTS) confirmed parathyroid hyperplasia. Two weeks later, the patient developed a swelling in the mandible on the right side increasing gradually. The facial X-ray showed osteolytic lesions related to a BT. A 61-year-old woman with hypertension and undergoing dialysis two times per week since 2016 showing secondary hyperparathyroidism with a level of PTH at 4200 pg/ml, a calcemia level at 2.3 mmol/l and a phosphoremia at 1.3 mmol/l. Cervical ultrasonography showed hypertrophy of the parathyroid glands. An x-ray of the crane revealed lacunar lesions and pepper and salt signs. Bone demineralization of the vertebrae was noted in the spine. In addition, there was a subperiostal resorption of the phalanges. The CTS of parathyroid confirmed parathyroid hyperplasia. Meanwhile, we discovered a 0.5 cm diameter swelling situated in the medial third of the right clavicle related to a tissue-density central medullar lesion and which blows the matching cortical in the CTS related to a BT. A 24-year-old girl who is undergoing hemodialysis since 2011. Her medical story includes congenital hips dislocation and heart insufficiency. She presented after 8 years of dialysis a secondary hyperparathyroidism with a level of PTH at 1700 pg/ml, a calcemia at 2.2 mmol/l, a phosphoremia at 1.3 mmol/l. She complained of left gonalgia without fever. Besides, there were no local inflammatory signs. An x-ray of the knee showed a regular osteolytic lesion at the lower third of the left femur. A CTS has showed a large osteolytic mass of the left ilio-pubic branch with small diffuse osteolytic lesions that break the cortical in the lower left femoral metaphysis bone, the left patella and the right tibial metaphysis bone related to BT. Our patients are treated by active and native vitamin D and will be referred for parathyroidectomy. Secondary hyperparathyroidism is a common complication of end-stage renal disease, on long time hemodialysis. That’s why measurement of PTH should be systematic in every patient undergoing dialysis to prevent BT.