In order to avoid the difficulties in scheduling and cost involved in admitting patients to hospital to undergo bone marrow harvests, we assessed outpatient marrow harvesting for autologous bone marrow transplant (BMT) candidates. Over a 13-month period, 39 consecutive patients with hematologic malignancies underwent bone marrow harvests as outpatients. For comparison we also evaluated 20 consecutive patients with similar disease status who had undergone bone marrow harvests as inpatients over the preceding 6 months. The mean hemoglobin value prior to harvest the mean volume of marrow harvested, and the mean nucleated cell count in the outpatient group were not significantly different from those of the inpatient group. There were no intraoperative complications. Of these 39 patients, 36 were discharged later the same day on oral iron supplements, with no adverse sequelae. Local pain was well controlled at home with mild oral analgesics. Two patients required admission due to postoperative hypotension--both responded promptly to intravenous (IV) fluids and blood and were discharged the following day. One patient was admitted postoperatively due to fever. There was a trend for the outpatients to receive less intra- and postoperative blood transfusions, but this did not reach statistical significance. The results suggest that most candidates for autologous BMT can safely undergo bone marrow harvesting as outpatients, thereby relieving pressure for hospital beds, potentially reducing costs and improving bed utilization. The study also raises the possibility of safely performing outpatient harvests on allogeneic BMT donors.