PURPOSE To compare autologous bone marrow (BM) with peripheral-blood progenitor cells (PBPC) as hematopoietic rescue after high-dose chemotherapy (HDCT). PATIENTS AND METHODS From January 1991 until April 1993, 47 consecutive patients with relapsed or refractory germ cell tumors were randomized to either BM harvest or collection of PBPC mobilized by chemotherapy plus granulocyte colony-stimulating factor (G-CSF). After additional conventional-dose salvage treatment, all patients received HDCT with carboplatin 1,500 mg/m2, etoposide 2,400 mg/m2, and ifosfamide 10 g/m2 with either BM or PBPC rescue. RESULTS Forty-six patients were assessable for hematologic reconstitution, and one patient died on day +4 before engraftment. Rescue using PBPC resulted in a significantly shorter recovery time to neutrophil counts more than 500/microL (10.0 v 11.0 days, P < .01), neutrophil counts more than 1,000/microL (10.0 v 12.0 days, P = .001), and platelet counts more than 20,000/microL (10.0 v 17.0 days, P < .01), as well as in fewer days to transfusion independence from RBCs (8.0 v 12.0, P < .05) and platelets (9.0 v 12.0, P < .01) and fewer days of intravenous (IV) antibiotics (9.0 v 11.0, P < .05). However, no statistical differences in transfusion requirements or in other clinical outcome variables were observed. Overall survival and event-free survival also were not different in the two study arms. CONCLUSION We conclude that the use of PBPC mobilized by chemotherapy plus G-CSF results in sustained trilineage reconstitution after HDCT, which occurs more rapidly as compared with BM. The earlier hematologic reconstitution in patients with PBPC rescue significantly reduces the time to transfusion independence.