Bartter's syndrome is a rare tubular disorder characterized by hypokalemic, hypochloremic metabolic alkalosis, hyperreninemic, hyperaldosteronism, hyporesponsiveness to pressor agents and juxtaglomerular apparatus heperplasia. We report a case of Bartter's syndrome of a 5 month-old male infant with subdural hematoma who was confirmed by characteristic clinical, laboratory findings and kidney biopsy.