We report the case of a 58-year-old woman with low-grade astrocytoma, who developed massive intracranial hemorrhage as the first presentation of this disease, and become comatose and subsequently underwent an emergency craniotomy. A small amount of tumor-like tissue was observed on the wall of the hematoma cavity. Histological analysis of the resected specimen indicated diffuse astrocytoma [World Health Organization (WHO) grade II]. The patient was discharged without neurological deficits 2 weeks after the operation. A non-enhanced tumor-like nodule was observed on magnetic resonance imaging 3 months after the operation, which was monitored carefully but was not treated by adjuvant therapy. The tumor grew gradually, and a second operation was performed 3 years after the first, in which the tumor was completely resected. Histological analysis of the resected specimen again indicated diffuse astrocytoma (WHO grade II). Although rare, brain tumors, including low-grade astrocytoma, should be considered a possible cause of subcortical hemorrhage in patients without risk factors for intracranial hemorrhage.