The role of radiotherapy in the initial management of small-cell lung cancer (SCLC) is a matter of current debate. Unfortunately, compared to other cell types, radiotherapy for SCLC is limited in its use. The value of radiation therapy in palliation is unquestioned. SCLC is quite sensitive to both radiation therapy and chemotherapy. However, in extensive disease radiation therapy is secondary to combination chemotherapy. In limited disease, it is well documented that thoracic irradiation increases locoregional tumor control and improves the complete remission (CR) rate. However, the patients given high-dose thoracic irradiation concurrently with chemotherapy are the possibility of local toxicity, especially, drug induced pneumonitis. Recently, the optimal sequence of radiation therapy and chemotherapy has been discussed. We believe that it is better to start with chemotherapy. With prolongation of survival related to intensive combination chemotherapy, brain metastases become more frequent. Therefore current therapeutic regimens include prophylactic cranial irradiation (PCI) soon after the attainment of CR, but it has not prolonged survival. So there are conflicting reports about neurotoxicity after PCI. It is difficult to reach any firm conclusion in regard to the value of PCI.