Intracerebral schwannomas are rare and there have been none reported in Korea. We present the case of a 25-year-old man with newly developed right-side weakness and recent seizure aggravation. His seizures started approximately 9 years prior to admission. At that time, a 1 cm diameter intra-axial enhancing mass at the left precentral gyrus was found on magnetic resonance image (MRI). After 9 years of observation and treatment with antiepileptic medication, an MRI taken due to symptom aggravation revealed peri-tumoral cyst formation with tumor enlargement. The tumor was surgically removed. Subsequently, right-side weakness diminished and there was good seizure control. Pathologic diagnosis was schwannoma. Schwannoma is a very rare tumor and there are no pathognomonic findings on radiologic images; thus, it is challenging to make a correct diagnosis. However, considering the natural course and excellent prognosis after surgical treatment of this kind of intra-axial mass with benign features, early surgery for diagnosis and proper treatment is highly recommended.