Background: Rasmussen’s encephalitis (RE) is a rare, chronic inflammatory neurological disorder that typically affects children. It is characterized by progressive focal seizures, cognitive decline, and unilateral brain atrophy . Early identification is crucial for managing the patient's neurological development and quality of life. This report discusses the clinical findings and MRI characteristics of a 9-month-25-day-old male infant who presented with persistent, treatment-resistant seizures. Case presentation: The patient presented with a history of recurrent seizures that were unresponsive to conventional antiepileptic therapy . To rule out metabolic or other common causes of seizures, an extensive diagnostic workup was conducted. Significant investigations, including serum electrolytes, serum calcium, RBS (Random Blood Sugar), and EEG, all yielded normal results. Given the persistent and refractory nature of the seizures, an MRI of the brain was subsequently performed to investigate potential structural abnormalities. The MRI examination revealed significant findings, most notably left-sided hemiatrophy associated with ex-vacuo ventriculomegaly and encephalomalacia. There were marked signal changes in the cortical and subcortical regions of the left hemisphere. The extraventricular CSF spaces appeared widened. Importantly , the internal and external capsules, basal ganglia, and thalamus appeared normal bilaterally . Other structures, including the midbrain, pons, cerebellum, and pituitary gland, were unremarkable Conclusion: This case highlights the importance of neuroimaging in the evaluation of infants with persistent, drugresistant seizures, particularly when initial metabolic and electrophysiological investigations (like serum electrolytes and EEG) are normal. The MRI evidence of unilateral hemiatrophy and encephalomalacia in this infant strongly supports a diagnosis consistent with Rasmussen’s encephalitis. Given the complexity and progressive nature of this condition, it is imperative that the patient be under the continuous care of a specialist (pediatric neurologist) to discuss therapeutic strategies to optimize the patient’s longterm neurological outcome.