In nine patients with recurrent or refractory small cell lung cancer a phase II study with high-dose cyclophosphamide and high-dose VP 16-213 with autologous bone marrow transplantation was performed. The regimen used was based on a previously reported phase I study. In eight of the nine evaluable patients a response was seen (six PR and two CR). One patient died of treatment related toxicity. Infection is the most important toxicity. The response duration was short. This combination is a suitable "late intensification' regimen for patients with minimal residual disease after standard dose induction chemotherapy.