The prognosis for non-small-cell lung carcinoma (NSCLC) pat ients in advanced stages is poor. Gefitinib inhibits the tyrosine kinase activity of epidermal growth factor receptor (EGFR) and have been studied extensively. Oral epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have been as the 2nd-line treatment for NSCLC. It is widely accepted that some clinicopathologic characteristics (female, nonsmoking status, Asian, and EGFR mutations) are the main clinical positive predictive factors when using EGFR-TKIs. The el der patients often suffer from deterioration of performance status (PS). The side reaction caused by chemotherapy is serious and unavoidable. For the elder patients with positive predictive factors and poor PS, there is no report about anti-NSCLC using gefitinib as the 1st-line treatment. We report the case of an 84-year-old woman with diffuse bone metastases from lung cancer. She received oral gefitinib 150 mg / day, combined with three dimensional conformal radiation therapies (3DCRT). A total tumor dose of 36Gy / 12fractions was delivered to the tumor bed and localized metastatic bone pain areas, respectively. After concurrent gefitinib-3DCRT, gefitinib was continued as maintenance therapy. She experienced total regression of the metastases under gefitinib treatment for 30 months. Gefitinib therapy provided effective anti-tumor results. Therefore, for NSCLC patients of multiple metastases with favorable predictive factors such as EGFR mutations, adenocarcinoma, Asian, female gender and nonsmoking status, we suggest that gefitinib may become the 1st-line treatment even with poor PS. doi:10.4021/jmc513w