Résumé : Following three courses of induction chemotherapy, 23 patients with small cell carcinoma of the lung were treated with a late intensive regimen including autologous bone marrow infusion. Thirteen patients received high doses (2 or 3 times the induction chemotherapy dosage) of cisplatin, adriamycin and etoposide. One patient was probably cured, but renal and mucosal toxicity was observed. Three patients treated with adriamycin, etoposide and cyclophosphamide also developed severe mucositis. The 7 remaining patients received high doses of cyclophosphamide (100-200 mg/kg) and etoposide (750-1000 mg/m2); responses were obtained with moderate toxicity. The long-term survival is not yet known. The usefulness of bone marrow infusion cannot be determined without further studies.