It has been reported that the expression of excision repair cross-complementation group 1 (ERCC1) protein predicts the effect of platinum-based chemotherapy and overall survival in the several cancers. And there are some reports suggesting that the polymorphism of the ERCC1 may predict the effect of platinum-based chemotherapy and survival of the patients. We have already reported that the expression of ERCC1 protein predicts survival after platinum-based chemotherapy for 90 completely resected non-small-cell lung cancers (NSCLC).We investigated the ERCC1 polymorphisms (C8092A and C118T) whether these factors influence for the prognosis of these 90 NSCLC patients treated with platinum-based chemotherapy.Two of the ERCC1 polymorphisms, C8092A and C118T, affected the prognosis of the NSCLC patients who received adjuvant and/or neoadjuvant platinum-based chemotherapy. The wild type, C/C of the codon 8092, was associated with better prognosis than C/A or A/A types (P=0.0154) and the wild type C/C of the codon 118 was associated with better prognosis than C/T or T/T types (P=0.0307). This effect was not seen in an independent group of 55 completely resected NSCLC patients who were treated with surgery alone. The combination of low expression of ERCC1 protein together with the C/C type codon 8092 and C/C type codon 118 polymorphism of the ERCC1 gene was associated with the best prognosis.Our data seem to suggest that the ERCC1 protein expression and polymorphism of ERCC1 may predict the survival of patients who are treated with platinum-based chemotherapy.