Biomarkers for lung cancer may be used for early detection, diagnosis, treatment selection and prognostication. They are also expected to contribute to the realization of tailored therapy. To identify the optimal therapy candidates, EGFR (epidermal growth factor receptor)mutations are biomarkers available as predictive factors for EGFR tyrosine kinase inhibitors and UGT(uridine diphosphate glucuronosyltransferase)1A1 as a risk predictor of irinotecan in the present practice. Novel potential biomarkers for prognostication have been developed by genomic methods. Biomarker development for early detection is much awaited for the future.