We report a case of renal sarcoidosis accompanied by hypercalcemia and renal insufficiency. A 52-year-old woman presented to hospital with nausea, pruritus, general weakness and weight loss. Laboratory tests revealed a serum creatinine was 3.6mg/dL, calcium ll.lmg/dL(ionized calcium 5.6mg/dL), hemoglobin 10.2g/dL, parathyroid hormone <3.0pg/mL, 24 hour urinary protein 1,127mg/day and 24 hour urinary calcium 489mg/day. Chest X-ray showed normal and both kidneys were within normal size with mild increased echo-genicity on renal ultrasound. Renal biopsy showed interstitial nephritis with mononuclear cell infiltration and mild interstitial fibrosis. Non-caseating granuloma with epitheloid and giant cells were seen. Following corticosteroid therapy, renal function and hypercalcemia were dramatically improved. Within 1 month, calcium level was normal and the creatinine level fell to 2.0mg/dL and subsequently remained stable while corticosteroid was progressively tapered off. She has been followed up for 11 months with normal seum calcium level and the creatinine level of 1.9mg/dL.