One-hundred and twenty-five patients who had undergone surgery for intraparenchymal brain metastasis (solitary or multiple) at The Center for Adult Diseases, Osaka, between 1978 and 1988, who had been followed-up until July, 1989 were reviewed. Statistical evaluation of various prognostic factors was performed on the basis of the median survival time after tumor removal for 103 patients after excluding 14 patients who died within 30 days after tumor removal and 8 patients with incomplete medical records. The lesions responsible for death, which included metastasis, carcinogenic tumor in organs other than the brain and treatment-related lesion, and change in performance status after surgical resection as assessed by the score on the Karnofsky scale were also investigated to evaluate the effect of surgical therapy. The overall median survival time of the series was 6.0 months, with a 1-year survival rate of 18%. Favorable prognostic variables showing statistical significance included a preoperative performance status above 40% on the Karnofsky scale and the presence of only brain metastasis, without any metastatic deposits or primary lesions outside the brain. Other favorable prognostic factors, which were not significant on the basis of statistical tests, were an age of under 65, surgical excision of the primary lesion, absence of a primary lesion, absence of metastatic lesions, solid type of tumor, supratentorial location of the tumor, and the use of adjuvant therapy if the tumor is not resistant to chemotherapy and/or radiotherapy. The factor of the free interval was not found to be significant. Regarding the cause of death, only 26% of nonsurvivors died of the brain lesion itself; 69% died of systemic cancer outside the brain.(ABSTRACT TRUNCATED AT 250 WORDS)