Worldwide, approximately 1.3 billion individuals are current smokers, and smoking is the second major cause of death. Currently, lung cancer is the most common type of cancer in Europe, and the third in the U.S. Until now, cytotoxic chemotherapy has had a limited impact on survival in metastatic non-small cell lung cancer (NSCLC). The central role of epidermal growth factor (EGF) and its receptor (EGFR) in lung carcinogenesis is well recognized. Genetic polymorphisms are variants in individual genomes that may be responsible for different functional molecular roles and contribute to variability in drug pharmacokinetic and pharmacodynamic processes. Herein, we review the literature on EGF and EGFR functions and activities, particularly the current role of their functional polymorphisms as related to NSCLC.