Advanced non-small cell lung cancer is associated with a low rate of long-term survival and a range of painful and debilitating symptoms. Various self-report questionnaires have been developed to monitor non-small cell lung cancer-related symptoms and quality of life over the course of treatment. The Functional Assessment of Cancer Therapy-Lung questionnaire is a widely used and well-validated lung cancer-specific instrument. It has been used to assess quality of life in numerous lung cancer clinical trials investigating a variety of therapeutic agents, including chemotherapy, radiation therapy, and targeted therapy. The Functional Assessment of Cancer Therapy-Lung is predictive of both tumor response and patient survival, and has been found to be highly sensitive to changes in clinical indicators.