Lung cancer is the leading cause of cancer-related death in US and Europe. Treatment with a platinum-based chemotherapy remains the standard of care, however with modest effect on quality of life and overall survival which seldom reaches 1 year. Recently, several classes of targeted agents have emerged showing promising results. In particular, agents targeting the epidermal growth factor receptor (EGFR) showed impressive clinical activity both in the first line and salvage settings. However, it is evident that these drugs are not effective in all patients. Putting into consideration the very high cost of these agents, there is an urgent need to provide reliable tools to identify those patients that would derive the maximum benefit from these drugs. Several predictive biomarkers were developed to identify those patients who would derive the maximal benefit of these drugs. In this review we will discuss the recent updates on the role of EGFR inhibitors in the treatment of advanced NSCLC and the role of predictive bio-markers in patient selection.