Every thoracic oncologist could be considered a geriatric oncologist as the median age of presentation with metastatic non-small-cell lung cancer is 71 years. Subgroup analyses and population-based studies suggest similar benefits to treatment of the fit elderly compared with younger patients. In 2011, a Phase III trial demonstrated the superiority of doublet chemotherapy over single-agent therapy for the elderly. For elderly patients there has been sufficient time to fully express any genetic predispositions, and the cumulative wear and tear, including the effects of cigarette smoke, can degrade performance status and impair organ function, leading some older patients to be less fit. Comprehensive geriatric assessment can augment the standard examination in defining the strengths and weakness of the elderly patient who is considering chemotherapy. In the future, biochemical assessment of physiologic age may further aid this assessment.