Sarcoidosis is a granulomatous disorder with multiorgan involvement which may appear in an isolated form but more often as a systemic disease. We report the case of a 53-year-old woman presenting with acute renal failure, hypercalcemia, elevated 1.25 dihydroxycholecalciferol, and a history of fatigue, weight loss and arthralgia of several months. Kidney biopsy had revealed interstitial noncaseating granulomas, so sarcoidosis was considered as a potential diagnosis after exclusion of other granulomatous disorders. Granulomatous tubulo-interstitial nephritis (GIN) is an uncommon disease with a low, but perhaps underestimated incidence: only about 100 cases have been described in the literature. In these cases it was found that the disease may lead to deterioration of renal function and irreversible progress to end-stage renal disease. The treatment of choice is the administration of steroids.