In Thailand, bladder stone is a highly endemic disease in children in two of four distinct geographic regions of the country, the North and Northeast. Vesical stones occur early in life; a median age of 5 years has been reported in Ubon Province, and they are seen 8 times more frequently in males than in females. Preliminary observations suggest that bladder stones are more common in rural than in urban areas and that recurrence rates are low (less than 1%). No adequate hypothesis for the pathogenesis of bladder stone exists, although extended observations of this condition in Thailand and elsewhere strongly implicate a deficiency or excess of some human nutritional factor(s). The early age of onset of bladder stone suggests the possibility of the transmission of a lithogenic factor in human milk. This hypothesis may serve as a departure for the additional epidemiological and clinical studies which are needed to clarify our understanding of this problem.