Dyspnea is a subjective symptom defined as an experience of uncomfortable and difficult breathing which strongly affects the quality of life. It is the most common symptom in lung cancer but its physiopathology remains unclear. Dyspnea is due to cancer itself, specific therapies or comorbidities. To evaluate intensity of dyspnea, analogue visual and verbal rating scales need to be preferred. Diagnosis of underlying cause, based on rational and non invasive strategy is needed to perform effective treatment if possible. Despite its frequency, few therapies are really effective, except nonpharmacologic measures: only morphine can be actually recommend, especially with naive patients. In palliative cases, if dyspnea is uncontrolled, benzodiazepine can be used and may represent ethic approach.