Gefitinib is active and well tolerated in patients with advanced non-small cell lung cancer (NSCLC); however, its role in patients with brain metastases has not been clearly defined. We had conducted a prospective study to give gefitinib to NSCLC patients irrespective of their performance status (PS), number of prior treatment regimens and the presence of brain metastases. A total of 76 patients were enrolled. Fifty-seven patients had measurable lesions and the objective response rate was 33.3% (95% confidence interval [95% CI], 20.7-46.0%). For all enrolled patients, the disease control rate was 63.2% (95% CI, 52.1-74.3%) with a median progression-free survival of 5.0 months (95% CI, 3.6-6.5 months) and median overall survival 9.9 months (95% CI, 4.9-14.8 months). Twenty-one patients had simultaneously assessable intracranial lesions (ICLs) and extracranial lesions (ECLs), 17 of them (81.0%) showed comparable tumor response. There was no survival difference between the patients with and without metastatic brain disease. Most drug-related adverse events were mild. Intolerable toxicities happened in five patients, four of them were interstitial pneumonia (5.8%). Severity of skin toxicity was tightly associated with tumor response and patient survival (P = 0.007 and <0.001) and the association was consistent in the analysis using early toxicity profile (P = 0.033 and 0.001). In conclusion, gefitinib is active in patients with brain metastasis from NSCLC and tumor response is related to skin toxicity. It is feasible to conduct randomized trials to identify the role of gefitinib alone or in combination with other modality for treatment of NSCLC patients who have metastatic brain lesion(s).