Cytinuria is an inherited disorder of cystine and dibasic amino acids involving renal and intestinal transport mechanisms. The only clinical manifestation of this disease is the development of urinary tract cystine stones. Cystine stones frequently occur in the second or third decade of life, with an occasional occurrence in infancy and in old age. In this article, a one-year old girl with cystinuria and urolithiasis is presented. This infant was hospitalized because of body trauma. Ultrasound examination revealed an unexpected finding of kidney multiple stones in the right kidney. A positive cyanide – nitroprusside test suggested cystinuria as a cause of nephrolithiasis. We studiet M467T and M467K mutations (exon 8) in rBAT gene and 231T/A polymorphism (exon 1). Our patient was heterozygous for the M467T mutations. We emphasize the significance of treatment in recurrent stones. Anahtar Kelimeler : sistinüri, üriner taş,cystinuria, urolithiasis