Desmoplastic infantile astrocytoma is a huge cystic tumor, typically occurring in the cerebral hemispheres of infants. The authors report a 4-month-old baby presented with increased head circumference, bulging fontanel, and the setting-sun sign. Magnetic resonance imaging revealed a round mass with huge cystic component in the right cerebral hemisphere. Microsurgical gross total resection of the tumor was performed and pathological examination of the specimen showed features of desmoplastic infantile astrocytoma. The postoperative course was complicated by subdural hygroma which was managed by the placement of subduroperitoneal shunt. Although desmoplastic infantile astrocytomas are rare, it must be distinguished from other hemispheric tumors in infancy or childhood because of good prognosis.