Thirty-three patients with advanced solid tumors were treated by high-dose chemotherapy (combined high-dose melphalan), followed by cryopreserved autologous bone marrow transplantation (ABMT). Thirteen of them had bone marrow (BM) tumor involvement at diagnosis, and BM harvest was purged with 50 micrograms/ml ASTA Z 7557 before cryopreservation. Following incubation, in vitro growth of granulomonocytic colony-forming cells (GM-CFC) was regularly inhibited (greater than 99%). Hemopoietic reconstitution after purged and nonpurged ABMT was studied. All patients experienced engraftment. However, peripheral leukocyte and granulocyte recoveries were delayed significantly in patients receiving purged BM (mean 27 and 26 days) compared with those observed in patients receiving nonpurged BM (mean 18 and 18 days). These results confirm that purged BM, despite GM-CFC depletion after in vitro treatment, ensures engraftment after high-dose chemotherapy, but prolonged pancytopenia is observed and postgraft hemopoietic recovery is delayed. A clinical trial is necessary to evaluate the efficiency of the purging technique in eradicating residual tumor cells.