Rasmussen’s syndrome is a neuroimmune disease characterized by progressive unilateral cerebral dysfunction, for which hemispherectomy remains the definitive treatment. We report a 9-year-old right-handed Filipino girl with drug-resistant focal seizures, epilepsia partialis continua, and progressive right hemiparesis due to left hemispheric involvement. Epilepsy surgery was not immediately feasible because of parental concerns and logistical constraints in this resource-limited setting. Despite treatment with multiple antiseizure medications, seizures remained uncontrolled, prompting initiation of immunotherapy with intravenous immunoglobulin followed by rituximab. Rituximab was associated with marked seizure reduction and functional improvement, highlighting its potential role in the management of Rasmussen’s syndrome when surgery is not feasible.