25 patients with poor-prognosis malignancies were treated with a combination of fixed-dose etoposide (1750 mg/m2), cyclophosphamide (6400 mg/m2) and escalating doses of carboplatin (from 800 to 1600 mg/m2) followed by autologous bone marrow transplantation (ABMT). The median duration of granulocytopenia (< 500/mm3) and thrombocytopenia (< 20,000/mm3) was 23 days and 20.5 days, respectively. The main non-haematological toxicity was gastro-intestinal, with moderate to severe diarrhoea in 15 patients. No significant renal toxicity was observed. 2 patients died early due to toxicity. The overall response rate was 58% including 42% having complete responses. 4 of the 25 patients are alive with no evidence of disease at 22, 27, 40 and 43 months after ABMT. The encouraging antitumoral activity of this regimen makes it a good candidate for intensified chemotherapy in patients with various malignancies. Toxicity is acceptable and may be reduced in the near future with the widespread use of haematopoietic growth factors.