According to WHO, 25% of lung cancer worldwide occurs in lifelong never smokers. Lung cancer in never smokers (LCINS) shows many clinical, epidemiological, molecular and genomic differences comparing to tobacco-related neoplasm. So, it is now considered as a separate entity. LCINS particularly occurs in women and Asian. They are mainly adenocarcinoma. Known risk factors are occupational exposure, environmental tobacco smoking, familial history of cancer, personal medical history of lung disease or environmental causes. LCINS carries more frequently molecular abnormalities leading to efficacy of targeted therapies (EGFR mutation, EML4-ALK inversion, less frequent mutations of KRAS ...). However, most data come from retrospectives studies, subgroups analysis and/or from Asian cohort even though it is a disease with a significant geographic variability. Finally, few studies focus on correlations between risk factors and molecular or genomic abnormalities.