Until recently, the collection of peripheral blood progenitor cells (PBPC) has been semi-automated by using the COBE Spectra™, with the operator manually maintaining the position of the white cells being collected. The COBE Spectra™ Version 6.0 apheresis device offers the user an automated program for the collection of PBPC. In this study, we compared the new software Version 6.0 to that of Version 4.7. Patients (n)64ס undergoing PBPC collection were allocated to cell processing with either Version 4.7 (n)42ס or Version 6.0 (n.)22ס The CD34+ cell count, mononuclear cell (MNC) count, white cell count (WCC), hemoglobin (Hb), and platelet content in the autograft product by using the two versions were compared. We divided the analysis into three subsets according to peripheral blood (PB) CD34 content: <10×10 6 /L, 10-50×10 6 /L and >50×10 6 /L. Analysis of the three subsets showed no statistical difference between results obtained when the starting PB CD34+ cell count was 10-50×10 6 /L (P)80.0ס or >50 ×10 6 /L (P.)5604.0ס At lower starting PB CD34+ cell counts of <10×10 6 /L, Version 4.7 was superior (P.)7610.0ס However, autograft platelet contamination of the autograft was significantly higher using Version 4.7 (P.