Since May 1999, the institutional guidelines of Samsung Medical Center, Seoul, Korea, have required preoperative magnetic resonance (MR) screening of the brain in all patients with lung adenocarcinoma. To investigate the brain metastasis and survival rates since the adoption of this guideline, we retrospectively reviewed the medical records of patients who underwent complete lung resection between January 1995 and December 2000. Recurrence rate, recurrence site, and survival were investigated and compared between patients with lung adenocarcinoma who underwent complete resection before May 1999, who did not undergo MR screening of the brain (non-MR group, n=160), and those after May 1999, who did receive MR screening of the brain (MR group, n=86). The brain metastasis rate was lower in the MR group than in the non-MR group (p<0.05), especially for the first 2 years. However, the recurrence rate at sites other than the brain was similar between the two groups. The 5-year survival was higher in the MR group (59%) than in the non-MR group (45%, p<0.05). Even in patients with stage I cancer, brain metastasis was diagnosed more frequently in the non-MR group (5%) than in the MR group (2%). Preoperative MR screening of the brain can help early detection of brain metastases in the patients with lung adenocarcinoma prior to surgical resection and lead to increase postoperative survival in patients with operable lung adenocarcinoma.