Cystinuria is an autosomal recessive disorder of dibasic amino acid transport in in kidney and intestine leading to increased urinary cystine excretion and nephrolithiasis. Two genes, SLC3A1 and SLC7A9, coding for rbaT and bO,+AT, account for the genetic basis of cystinuria. This study reports the clinical characterization and SLC3A1 (type A) and SLC7A9 (type B) mutations identified in a French cystinuria cohort. A total of 106 patients from 97 families with cystinuria and 18 relatives were investigated. A questionnaire addressing, age at first symptoms, stone recurrence rates, metabolic evaluations, medical therapy and follow-up was completed.