The signs and features of early-stage primary glioblastoma multiforme(GBM)are not well-characterized. Here, we report a case of GBM that was presented at an early stage and showed extremely rapid progression within a short period. A 63-year-old woman was incidentally revealed to have a tiny lesion in her right parietal lobe. Magnetic resonance imaging(MRI)showed a hyperintense signal on T2WI, with a ring-enhancement on gadolinium(Gd)-enhanced T1WI. Two weeks later, she was admitted to our hospital for neurosurgical intervention;the MRI at that time showed rapid tumor growth, immediately followed by progressive neurological deterioration. The tumor was urgently removed;its histopathological diagnosis was GBM. This case indicates that primary GBM, even at an early stage, can rapidly progress within an extremely short period. Scheduling prompt neuroradiological assessments and neurosurgical interventions in possible cases of early-stage GBM are important, especially if a Gd-enhancement is seen on MRI.