The paper presents the case of a four-month-old infant with a history of crying spells, vomit and renal stones on ultrasounds. Urinary excretion of dibasic amino acids and genetic study confirm a digenic cystinuria. The presented case shows that clinical features of nephrolithiasis in infants could be non-specific and the diagnosis challenging. Chronic renal failure is a possible complication of cystinuria and is positively related to the duration of the disease and treatment delay. Early diagnosis and treatment of cystinuria is essential in children to maintain a normal renal function and reduce the risk of end-stage renal disease in the more aggressive forms.