A late preterm infant of South Indian ethnicity born of a second-degree consanguineous marriage presented on the fourth day of life with severe neonatal hyperbilirubinaemia (NNH), rapidly progressing to bilirubin encephalopathy. The underlying cause was G6PD deficiency, a significant contributor to severe NNH, especially in late preterm neonates. The infant underwent an urgent double-volume exchange transfusion to manage hyperbilirubinaemia. Despite the intervention, long-term follow-up revealed complications of bilirubin-induced neurological dysfunction, including dystonia and bilateral sensorineural hearing loss. This case highlights the critical need for early screening and management of G6PD deficiency to prevent chronic morbidities. It underscores the importance of universal newborn screening, which is not well established in South Asian countries, including India, and vigilant postnatal monitoring, particularly in preterm infants, to mitigate the risk of long-term neurodevelopmental disabilities. Prompt intervention through measures such as exchange transfusion can be life-saving, but preventive strategies remain the cornerstone for better outcomes.