Introduction: Breast cancer is the most frequent malignancy in women and is curable in ~70-80% of patients with early-stage detection and without complication. Paraneoplastic neurologic syndrome of breast cancer is one such complication which is often hard to diagnose, severely debilitating, and also challenging to treat. Materials and Methods: A 57-year- old woman with no known co-morbidity presented with sudden onset altered sensorium. She was in status epilepticus when brought to emergency and progressed to super refractory status epilepticus in-spite of our efforts. MRI of the brain with contrast done revealed hyper intense signal in bilateral frontal, parietal, occipital, bilateral thalami, periaqueductal region and dorsal midbrain. Cerebrospinal fluid (CSF) study revealed only increased protein. The comprehensive infective panel of CSF was negative. The vasculitis marker, anti NMO and anti MOG antibody were absent. So, we suspected a possibility of autoimmune aetiology and started methylprednisolone along with intravenous immunoglobulin. Results: Her epileptic discharges settled in an electroencephalogram, and we weaned her off ventilation. We detected a right breast mass on clinical examination. The PET CT scan revealed metastasis in the liver, bones, right axillary lymph nodes, and bone marrow. Conclusion: Our patient, who had the first-time presentation, was diagnosed to have paraneoplastic encephalopathy in the background of breast cancer. The importance of proper clinical examination and whole-body PET CT scan, followed by a trial of immunomodulator therapy, is necessary in all patients with non-infective encephalitis.