Various types of brain tumors may cause hemorrhage. The purpose of the study was to examine the clinical relevance of tumor hemorrhage and the hemorrhagic mechanism from the pathologic viewpoint. We retrospectively reviewed 761 consecutive brain tumor cases according to clinical, operative, and pathologic records. Pituitary adenomas and recurrent tumors were excluded. Twenty-seven patients (17 men and 10 women, mean age, 50 years) with brain tumor hemorrhage were identified, resulting in an incidence of 3.5%. In 632 cases of primary brain tumors, there were 15 cases with hemorrhage, resulting in an incidence of 2.4%. There were 12 cases of brain tumor hemorrhage in 129 patients with metastatic tumors, for an incidence of 9.3% Among hemorrhagic cases, 63.0% of patients presented with acute onset of clinical deterioration. In 72.7% of gliomas with hemorrhage, hematoma appeared within the tumor, and 75% of metastatic brain tumors with hemorrhage were intracerebral hemorrhages around the borders of the tumors. The highest hemorrhage rate for primary brain tumors occurred in pilocytic astrocytomas, while the highest hemorrhage rates in secondary tumors occurred in metastatic thyroid papillary carcinomas and hepatocellular carcinomas. In our pathology study, increasing intratumor vascularization with dilated, thin-walled vessels and tumor necrosis were the most important mechanisms of hemorrhage.