A 33-year-old man presented with a minute tumor incidentally detected by magnetic resonance (MR) imaging screening. 1.5 Tesla MR spectroscopy indicated normal brain tissue whereas 3.0 Tesla MR spectroscopy indicated neoplasm. The tumor was completely resected. The histological diagnosis was fibrillary astrocytoma. Minute glioma, measuring less than 15 mm in diameter on MR imaging, can be completely resected, resulting in a good prognosis. 3.0 Tesla MR spectroscopy can establish the diagnosis in the early stage of glioma.