Urinary retention caused by a urethral cystine stone in a 10-month-old infant.

Urinary retention resulting from urolithiasis in early infancy is an extremely rare event. Cystine stone formation in those younger than 1 year is also a rare condition. We report a case of urinary retention caused by a urethral cystine stone in a 10-month-old male infant. Obstructive urolithiasis should be considered one of the reasons of decreased urine output in infants.