We report 14 normal peripheral blood stem cell (PBSC) donors > or = 60 years of age who had cytokine mobilization followed by PBSC apheresis for allogeneic transplantation. Mobilization was achieved with filgrastim (6 microg/kg twice daily). Their median age was 63.5 years (range 60-77), and 43% had a positive medical history, mainly hypertension and/or cardiac problems. Their median pre-apheresis leucocyte count (x 10(9)/l) was 38.6 (range 29.6-63.4). The median apheresis yield (x 10(6) CD34+ cells/litre blood processed, first apheresis) was 27.9 (range 1.6-54.8). The target cell dose (> or = 4 x 10(6) CD34+ cells/kg recipient) was reached with one procedure in eight (57%) donors. Filgrastim-related adverse events were acceptable and apheresis was well tolerated. When compared to younger donors (< 60 years of age), a trend to a lower CD34+ apheresis yield and a requirement for more than one apheresis to achieve the collection target (> or = 4 x 10(6) CD34+ cells/kg) was evident. Although older (> or = 60 years) donors seem to mobilize less effectively, these data suggest that PBSC collection from them is feasible and has an acceptable short-term safety profile.