Sarcoidosis has been associated with a wide spectrum of renal manifestations, including disordered calcium metabolism, nephrocalcinosis, nephrolithiasis, granulomatous interstitial nephritis, and glomerulonephritis. In some patients, two or more manifestations of renal sarcoidosis may coexist. The case of a young patient with sarcoidosis who presented with hypercalcemia and acute renal failure is discussed. Despite normalization of the serum calcium with intravenous fluids and corticosteroids, his renal insufficiency persisted. A diagnostic renal biopsy was performed to determine the etiology of his renal failure and was helpful in the selection of optimal medical therapy.