Antenatal Bartter syndrome is characterized by severe polyhydramnios in mother leading to premature delivery. Antenatal treatment has proven effective to prevent these problems. Postnatally newborns suffer from recurrent episodes of severe dehydration and electrolyte imbalance which can lead to fatal outcome. These manifestations are likely to be overlooked and missed under the umbrella of diagnosis of prematurity. This premature newborn with antenatal polyhydramnios had severe manifestations of polyuria, recurrent dehydration, electrolyte derangements and metabolic alkalosis. She was managed accordingly but unfortunately could not survive beyond 4 weeks.