Carnitine deficiency in paediatrics can present in infants with episodes of irritability, lethargy and hepatomegaly. The main treatment for primary carnitine deficiency is to take L-carnitine supplements. Here we report a case of a female neonate with carnitine deficiency. A female child of 1.5 kg of 34 weeks of gestation was admitted for low birth weight. Baby was discharged on 18th day of life. On 25thday of life, parents brought the patient back with complains of lethargy, where hypoglycemia was detected. After recovery, baby was shifted to full feed. Metabolic disorder was suspected. Extended neonatal screening test was sent and was suggestive of decreased levels of free carnitine in blood. For treatment, syrup L-carnitine was started. Signs and symptoms of primary carnitine deficiency typically appear during infancy or early childhood. Infants mostly present with hypoglycaemia. For treatment, carnitine supplements are provided