The most important progress made during the last years in the management of small cell lung cancer is certainly the recognition of the impact of chest radiotherapy for limited disease and prophylactic cranial irradiation (PCI) for patients in complete response. How to optimize chemotherapy and radiotherapy is the topic of this paper. The current trend is to deliver thoracic radiation concurrently with the first cycles of chemotherapy (cisplatine and etoposide). The total dose is still not defined and the subject of phase III trials. PCI is delivered at the end of the chemotherapy with moderate doses. The place of PCI in extensive disease is still debate even if there is a clear benefit in quality of life.