['We designed a prospective study to test epidermal growth factor receptor (EGFR) expression by immunohistochemistry (IHC) in resected stage I-IIIA non-small-cell lung cancer (NSCLC) and to correlate overexpression with survival.', 'EGFR expression was evaluated in 130 consecutive NSCLC patients after radical surgery (60 squamous cell carcinomas, 48 adenocarcinomas, 22 large cell carcinomas: stage I, 41 (31%); stage II, 37 (29%) and stage IIIA, 52 (40%).', 'Overall, 101 of 130 (78%) specimens expressed EGFR, and with a cut-off value of 10% positive cells 48 cases (37%) were classified as positive. At univariate analysis, EGFR was significantly more expressed in stage III (50%) than stage I (20%) and stage II (25%) (P <0.03). No correlation with histotype was found. After a median follow-up of 84 months, both median survival time (18 versus 50 months), 2-year (43% versus 70%) and 5-year (31% versus 46%) survival rates of positive cases were significantly lower than negative ones [P <0.001; hazard ratio 1.96; 95% confidence interval (CI) 1.16-3.30]. At the multivariate analysis, EGFR overexpression and stage emerged as independent factors for cancer-related mortality.'] Does epidermal growth factor receptor overexpression correlate with a poor prognosis in completely resected non-small-cell lung cancer?