Three male infants with vomiting, dehydration, hyponatremia, hyperkalemia and metabolic acidosis were found to have vesicoureteral reflux (VUR) and urinary tract infection. Two were initially thought to have the salt-losing form of congenital adrenal hyperplasia. Although prompt diagnosis of this potentially fatal condition is critical, its mimicry by urosepsis in infants with VUR is actually more common. Infection probably causes unresponsiveness of the distal renal tubules to aldosterone.