Twenty patients with disseminated cancer both untreated and previously treated received bialkylator chemotherapy, thiotepa, and cyclophosphamide and reinfusion of cryopreserved autologous bone marrow (ABMR). The cyclophosphamide dose was constant at 7.5 g/m2 over three days, while thiotepa was started at 1.8 mg/kg for three days in escalating dose by a modified Fibonacci schema to 7 mg/kg. The median time to recovery of more than 500 granulocytes and more than 50,000 platelets/microL was 18 and 27 days, respectively. Four patients died as a consequence of severe, overwhelming infections or progressive disease during their period of aplasia. Of the 18 evaluable patients, a complete response (CR) was achieved in three patients and a partial response (PR) in ten patients for an overall response rate of 72%. The median duration of response was 14 weeks. Other nonhematologic toxicities included nausea/vomiting, diarrhea, stomatitis, skin rash, and cardiomyopathy. The maximum tolerated dose (MTD) of thiotepa was 700 mg/m2 or 6 mg/kg for three doses. Although there are substantial toxicities associated with this regimen, high-dose thiotepa and cyclophosphamide produce high response rates in patients with disseminated cancer.