Introduction: Maple syrup urine disease (MSUD) is a rare autosomal recessive disorderaffecting branched-chain amino acid metabolism. Early diagnosis is crucial as delayed treatment can lead to severe neurological complications and death. This case highlights the importance of metabolic screening in neonates presenting with neurological symptoms. Case presentation: A 7-day-old term male neonate, born via normal vaginal delivery to nonconsanguineousparents, presented with increased tonicity of all four limbs. The infant had been feeding poorly for two days prior to presentation. Physical examination was unremarkable. Notably , no characteristic maple syrup odour was detected in the urine. Laboatory investigations showed elevated serum ammonia levels at 152 μmol/L. Arterial blood gas analysis was within normal limits with no evidence of metabolic acidosis. Blood glucose and electrolytes were normal. Given the clinical presentation and hyperammonaemia, metabolic screening was performed. Plasma amino acid analysis revealed significantly elevated levels of leucine + isoleucine (1304.177 μmol/L),Leucine/Phenylalanine (26.63),Leucine/Alanine(16.69) and valine (496 μmol/L) confirming the diagnosis of MSUD. The infant was immediately started on a branched-chain amino acid-restricted formula and supportive care. Seizures were controlled with anticonvulsants. The patient showed gradual clinical improvement with normalization of amino acid levels over the following weeks. Conclusion: MSUD should be considered in neonates presenting with unexplained seizures and hyperammonaemia, even in the absence of the characteristic urine odour. Early diagnosis through amino acid profiling and prompt dietary management are essential for preventing irreversible neurological damage.