Retrospective analysis was performed in 280 patients; 112 surgical cases and 168 non-surgical cases to determine which of three treatments, alone or in combination provides more prolonged improvement of performance status (PS: Karnofsky score) in patients with metastatic brain tumors from lung cancer. The treatments under scrutiny were surgical removal of metastatic brain tumor (S), radiation therapy (R) and chemotherapy (C). KS in the group treated with S or C showed a significantly better result than that in the non-S group or non-C group during the two-year observation period. However, R group showed no significant improvement in KS compared to that in the non-C group during the two-year period. During the first year after admission, two subgroups of S plus R and R alone showed most rapid decrease in KS. However, subgroups of S plus C and S plus R and C showed better results than other subgroups. In analyzing the changes in KS over the short period from admission to one month after treatment had been completed, the non-S group showed a significant decrease in KS, while the S group showed a slight increase in mean KS. The subgroup of R alone showed the greatest decrease in KS. Thus, retrospective analysis showed that surgical removal of a metastatic brain tumor led to improved KS for a short period and chemotherapy was useful in prolonging the duration of better Q.O.L.