Non-small cell lung cancer (NSCLC) is primarily a disease of the elderly. Although NSCLC is the leading cause of cancer death in the United States and the overall prognosis of this disease is poor, treatment improves survival compared with best supportive care, independent of the stage of disease. Elderly patients have a particularly poor prognosis with NSCLC compared with younger patients, likely due to age-related biases in referral and treatment patterns. There is an emerging literature regarding the tolerability of NSCLC treatments in elderly patients. In advanced disease, subgroup analyses of the elderly population participating in randomized clinical trials as well as elder-specific prospective randomized trials have demonstrated that elderly NSCLC patients derive equivalent survival benefit from the treatment of NSCLC as younger patients. This treatment is tolerable for "fit" elderly patients, and modified regimens are available for the more frail elderly patients. Evaluating the relative fitness of an elderly patient may be achieved through an assessment of functional ability. As the U.S. population ages and the incidence of NSCLC rises, an understanding of treatment options for elderly patients with NSCLC is vital for all clinicians involved in their clinical care.