Customized chemotherapy is increasingly used in the management of patients with advanced non-small cell lung cancer (NSCLC). However, the most reliable methodology to determine biomarker status is neither fully elucidated nor agreed upon. Accordingly, we evaluated the predictive efficiency of qRT-PCR and immunohistochemical analysis (IHC) on excision cross complementation group 1 (ERCC1), breast cancer susceptibility gene 1 (BRCA1), ribonucleotide reductase subunit M1 (RRM1) and class III ß-tubulin (TUBB3).