OBJECTIVE: To understand the prognosis of the children with urinary calculi associated with exposure to melamine-contaminated formula. METHODS: A follow-up study was performed in 47 out-patients from the Third Hospital of Peking University who were diagnosed with urinary calculi associated with exposure to melamine-contaminated formula. Urinary tract B-ultrasound and renal function examinations were done during the 1 to 6-month follow-up. RESULTS: By the 6th month of follow-up, spontaneous stone passage was found in 36 children (77%). The follow-up failed in four children. None of the patients had any complications. Spontaneous stone passage was not associated with the volume and the period exposed to melamine in formula, but was associated with the location of calculi. The time to spontaneous stone passage in boys appeared to be longer than in girls, but there were no statistical differences. CONCLUSIONS: Spontaneous stone passage can be found in most children and the prognosis of children with urinary calculi associated with exposure to melamine-contaminated formula is good.［Chin J Contemp Pediatr, 2010, 12 (4):278-279］