Lung cancer is classified histologically into small cell and non-small cell lung cancers. The most common symptoms of lung cancer are cough, dyspnea, hemoptysis, and systemic symptoms such as weight loss and anorexia. High-risk patients who present with symptoms should undergo chest radiography. If a likely alternative diagnosis is not identified, computed tomography and possibly positron emission tomography should be performed. If suspicion for lung cancer is high, a diagnostic evaluation is warranted. The diagnostic evaluation has three simultaneous steps (tissue diagnosis, staging, and functional evaluation), all of which affect treatment planning and determination of prognosis. The least invasive method possible should be used. The diagnostic evaluation and treatment of a patient with lung cancer require a team of specialists, including a pulmonologist, medical oncologist, radiation oncologist, pathologist, radiologist, and thoracic surgeon. Non-small cell lung cancer specimens are tested for various mutations, which, if present, can be treated with new targeted molecular therapies. The family physician should remain involved in the patient's care to ensure that the values and wishes of the patient and family are considered and, if necessary, to coordinate end-of-life care. Early palliative care improves quality of life and may prolong survival. Family physicians should concentrate on early recognition of lung cancer, as well as prevention by encouraging tobacco cessation at every visit. The U.S. Preventive Services Task Force recommends lung cancer screening using low-dose computed tomography in high-risk patients. However, the American Academy of Family Physicians concludes that the evidence is insufficient to recommend for or against screening. Whether to screen high-risk patients should be a shared decision between the physician and patient.