Cystinuria is an autosomal recessive disorder characterized by impairment of the proximal renal tubules which are unable to reabsorb cystine and dibasic amino acids, leading to the formation of recurrent kidney stones. According to the most recent genetic knowledge, there are two types of cystinuria. The disease is more severe in men than in women in terms of early appearance and number of produced stones. Renal function is generally maintained even after long-lasting disease. Type A heterozygotes are generally asymptomatic while type B heterozygotes usually have a three-fold increased incidence of kidney stones compared to the general population. Medical treatment of cystinuria with cystine-binding drugs and alkali is feasible and effective but requires continuous monitoring of free-cystine urine levels and urine pH and careful surveillance of side effects, with particular attention to the onset of proteinuria.