Within the last decade, many important discoveries were made in the regulation of growth, differentiation, apoptosis, and metastasis of lung cancers. These findings have dramatically changed the ignorance in the oncology community about the classification of lung carcinomas. A decade ago, oncologists were mainly interested to get the differentiation between small cell (SCLC) and non-small cell carcinomas (NSCLC) of the lung. With the findings of different responses for cisplatin and antiangiogenic treatment in adenocarcinomas versus squamous cell carcinomas, this simple clinical lung carcinoma classification schema was abolished. Now oncologists want to know the differentiation within NSCLC, and the near future will even require subtyping of different NSCLC entities. In this review, we will first focus on general aspects of molecular pathology in lung carcinomas and then discuss different genetic abnormalities within the different entities. These abnormalities will be ordered according to their importance such as targeted therapy and impact on outcome. We will focus on neoangiogenesis, DNA repair, receptor tyrosine kinases as oncogenic drivers, cell cycle checkpoints, and then specifically focus on genetic abnormalities in the different entities.