Supratentorial atypical teratoid rhabdoid tumors (AT/RTs) of infancy and childhood are rare, highly malignant neoplasms, most common in the first 2 years of life. In spite of multiple treatment regimens consisting of surgical resection, radiation therapy, and multi-agent chemotherapy, the prognosis is very poor. The majority of these tumors are located in the cerebellum, cerebellopontine angle, pineal gland, spinal cord, and the suprasellar region; supratentorial location is relatively uncommon, and the intraventricular location is extremely rare. We report a rare case of AT/RT arising in the lateral ventricle in a 4-year-old patient.