This chapter describes the diagnosis, treatment, and prognosis for lung cancer in pregnancy. The presenting signs and symptoms associated with lung cancer and pregnancy are similar to the nonpregnant state and depend mainly on the stage of the lung cancer. Lung cancer staging consists of physical examination in combination with surgical and radiologic investigations. The need for chemotherapy or radiotherapy during the early stages of pregnancy for rapidly progressive disease may lead to consideration of termination of pregnancy. The treatment of choice in early stage non-small cell lung cancer is curative surgical resection. Small cell lung cancer is characterized by an aggressive clinical course and relatively good response to chemo/radiotherapy compared to other types of lung cancer. When chemotherapy is administered during pregnancy, timing of delivery of the infant should take into account the expected bone marrow depression and potential problems such as bleeding or infections.