The therapeutic approach to the patient with non-small cell lung cancer (NSCLC) has undergone, in the last decade, a profound revolution following the marketing of molecularly targeted drugs. The launch of a vast research activity with the use of next generation sequencing (NGS) applied to liquid biopsy should be underlined. This last methodology, which allows to identify the correct biomolecular structure of the neoplastic population, has achieved significant progress in the effective implementation of personalized medicine. Nevertheless, the liquid biopsy represents a useful diagnostic strategy in those patients in whom a rebiopsia is difficult for technical reasons or for the patient's health conditions. The liquid biopsy represents a substantial cultural revolution opening a scenario in the identification of molecular drivers in the treatment of lung neoplasms.