The purpose of this study was to evaluate associations between germline epidermal growth factor receptor (EGFR) variants involved in transcriptional regulation and overall survival in white patients with non-small-cell lung cancer (NSCLC) treated with the EGFR tyrosine kinase inhibitor, gefitinib. Of 175 consecutive patients treated with oral gefitinib (250mg/day), 170 (median age: 67 years; 72% men) were evaluable for genotyping and survival. Fifty-five patients (33%) had stable disease and 17 (10%) had an objective response. The most common of four haplotypes was G-C (EGFR*1) at theEGFR- 216G>T and -191C>A loci (frequency, 0.45). After adjusting for performance status, previous platinum-containing chemotherapy and occurrence of skin rash or diarrhea during the first treatment cycle in patients with performance status 0 or 1 (N=139), the absence ofEGFR*1was associated with significantly better survival (hazard ratio: 0.54; 95% confidence interval: 0.32-0.91;P=0.015). The results may help identify patients with NSCLC who can benefit from gefitinib treatment.