Angiocentric glioma (AG) is an extremely rare tumor that often develops in adolescents. Awake surgery for AG occurring in the eloquent area has not been reported to date. We report a case involving a righthanded 15-year-old boy with AG. He presented with a first-time generalized tonic-clonic seizure and was rushed to the local hospital. CT of the head indicated a left frontal low-density mass with no calcification. He was subsequently referred to our hospital. Comparison with a CT scan obtained two years prior due to mild head trauma indicated that the lesion showed a trend toward enlargement. The lesion was located in the anterior and lateral portions of the primary motor cortex, and MRI showed homogenous hypointensity on T1-weighted and hyperintensity on T2-weighted images. Contrast-enhanced MRI showed a linear contrast effect. The patient underwent awake surgery with successful intraoperative brain mapping and total resection, and brain function was preserved. Pathological analysis revealed AG. He returned to his normal life and has shown no recurrence without additional treatment for 2 years. Thus, awake surgery for complete tumor resection while preserving brain function is effective and safe even in adolescents with AGs.