Hypercalcaemia is a frequent situation in clinical practice. An earlier detection is facilitated by routine analysis of serum calcium. The clinical manifestations depend on severity and the rate of onset of hypercalcaemia. Paucisymptomatic and asymptomatic presentations are the most frequent. Causes of hypercalcaemia are numerous and the mechanisms are various. PTH and vit. D play a preponderant part. In first of all iatrogenic cause are eliminated (all vit D preparations, thiazide diuretics, milk-alkali syndrome). Among non neoplastic hypercalcaemia primary hyperparathyroidism is the first diagnosis. Nephrolithiasis and asymptomatic forms are the most frequent presentations actually. The biochemical profile is not always typical. Generally the association of echography and tomodensitometry lead to the topographic diagnosis. Parathyroid surgical exploration is often necessary in difficult cases. Secondary, the other rare causes of hypercalcaemia are studied: sarcoidosis and granulomatosis disease, thyrotoxicosis and dome endocrinopathies, immobilisation hypercalcaemia, familial hypocalciuric, hypercalcaemia. All of this causes of hypercalcaemia are potentially reversible.