A case of neonatal Bartter syndrome is reported. The baby born pre-term following a pregnancy complicated by polyhydramnios, presented at 7 months of age with failure to thrive, gastroenteritis and facial dysmorphisms. An unusual feature was the absence of the classical biochemical abnormality of hypochloremic alkalosis early in the course of the disease. Metabolic acidosis was the initial manifestation at 5 weeks of age. Awareness of this presentation is important to avoid delay in diagnosis and treatment.