Improvements in small cell lung cancer (SCLC) therapy with conventional doses of drugs with or without radiotherapy have been poor, and the 5-year survival is discouraging. Since SCLC is highly sensitive to radiotherapy and chemotherapy, some studies have tried to improve survival by increasing the dose of the drugs. Within conventional ranges, dose intensity can be increased with the support of hematopoietic growth factors (G/GM-CSF) and/or shortening treatment intervals (eg weekly regimens). However, dose intensity could be increased by only 20-30% and a survival advantage was not definitively obtained. Given its high chemosensitivity already two decades ago, SCLC was one of the first malignancies deemed suitable for maximizing dose and dose intensity with the support of autologous bone marrow transplantation (ABMT). On the whole, results were disappointing and the procedure was nearly abandoned. Nowadays, some interest is emerging again due to the improvements in supportive care such as the availability of hematopoietic growth factors and the peripheral blood progenitor cells (PBPC).