Nephrolithiasis is a disease that could be defined as social, due to its widespread distribution and its continually increasing incidence in industrialized countries with a high standard of living (1). In Italy, it strikes just under 10% of the population, leading to expenditure of approx. 200 million euro/year for hospital admissions alone (2). Idiopathic Calcium Nephrolithiasis (ICN) with the formation of calcium oxalate stones, sometimes mixed with calcium phosphate ones, is the most common form, having an incidence of roughly 80% (3,4). As regards distribution in the two sexes, a slightly higher incidence in males has been observed. The pathogenesis of ICN involves both genetic and acquired factors (5), the combining of which leads to urinary biochemical anomalies which lie at the root of stone formation. A high rate of calcium-oxalate and/or calcium-phosphate supersaturation leads to the formation of nests of crystals that can then grow and aggregate to form a stone. The elements and urine compounds involved in the process of crystallization, whether they be inhibitors or promoters, are known as urinary stone risk factors. For Ca-oxalate they are: low urine volume (<2 l/day), hypercalciuria (>250mg/day), hyperoxaluria (>40 mg/day), hyperuricosuria (>600 mg/day), hypocitraturia (<320 mg/day) and hypomagnesuria (<50 mg/day). For Ca-phosphate, in addition to the above-mentioned factors, hyperphosphaturia (>1000 mg/day) and urinary pH also acquire considerable importance: a pH>7 promotes the formation of stones prevalently composed of phosphates, while a pH of between 6 and 7 associated with a urine volume <1l/day, can dangerously raise Ca-phosphate supersaturation and lead to the formation of mixed Ca-oxalate and Ca-phosphate stones. Finally, for uric acid stone disease the elements involved are hyperuricosuria and pH < 5.5. Among the stone risk factors, the most common found in the urine of patients affected by ICN is hypercalciuria with an incidence of around 50%. With regard to age of onset, there are two peaks, one between 20 and 30 years of age and one between 50 and 60.