The alveolar soft part sarcoma (ASPS) is a rare soft tissue tumor which usually occurs in the lower extremity of young girls. The incidence of metastasis is said to be highest in the lung (38%), and second highest in the bone and brain (33%). This report describes two cases of metastatic intracerebral alveolar soft part sarcoma, originating in the lower extremity. A female patient noticed a painless swelling in her right leg at the age of 11, and 10 years later she underwent total removal of the tumor. The diagnosis was alveolar soft part sarcoma. At 37 she was admitted to our service with a diagnosis of cerebral metastasis in the left frontal lobe. Since then she has undergone surgical removal 4 times for recurrent cerebral metastasis and twice for lung metastasis. Now she is 55 years old and doing well except for mild left hemiparesis. She survives without cerebral or general metastasis 44 years following the onset of the sarcoma in her right leg and 18 years following the onset of the metastatic brain tumor. A 30-year-old man, who noticed a painless swelling in his left thigh in January 1991, underwent total removal of the tumor and the diagnosis was alveolar soft part sarcoma. He was admitted to our service with no neurological deficits in October 1992, but a CT scan showed a metastatic brain tumor in the left parieto-occipital region. Total removal of this metastatic brain tumor was successfully performed in November 1992. However, he died because of multiple brain and lung metastasis in February, 1994.(ABSTRACT TRUNCATED AT 250 WORDS)