In an effort to evaluate the possible utility of cryopreserved autologous bone marrow infusions in man, 22 patients with malignant lymphoma resistant to conventional chemotherapy were treated with high- dose chemotherapy. This was followed in 12 patients by an infusion of their cryopreserved autologous bone marrow; 10 patients received chemotherapy alone and serve as controls. Following chemotherapy, severe leukopenia (less than 100 leukocytes/mm3) lasted 6–10 (median 8) days in patients receiving cryopreserved marrow, compared to 10–29 (median 16) days in controls (p less than 0.001). Recovery to 1000 leukocytes/mm3 occurred 10–18 (median 13) days after chemotherapy in autograft recipients but was delayed until 12–38 (median 23) days after chemotherapy in controls (p less than 0.001). Autografted patients also recovered granulocyte and platelet function significantly faster and had significantly fewer febrile days after chemotherapy than did controls. Cryopreserved autologous bone marrow infusions can hasten hemopoietic recovery in man after high-dose chemotherapy; this earlier reconstitution may be of clinical benefit to the patient.