We investigated the utilization patterns of autologous blood donation for radical retropubic prostatectomy (RRP) during a 6-year period. A total of 225 patients electing RRP with blood donation were identified for analysis. Group 1 consisted of 113 men who had an RRP from 1990 to 1993. Group 2 consisted of 112 men who had an RRP from 1993 to 1995. Charts were reviewed for the number of units transfused, number of autologous units donated, and operative blood loss. More patients autodonated blood in the later group (84% vs. 75%). Technical improvements and experience have significantly decreased blood loss and the need for transfusions (69% vs. 96% in the early group). In the more current series, only 14% of patients who autodonated blood required homologous transfusion vs. 42% in the earlier group. An increase in the amount of wasted blood (42% vs. 16% in the early group) also was noted. The 4-unit donors had the lowest homologous transfusion rate in both series (group 1 = 21%, group 2 = 5%); the 2-unit donors had the lowest units wasted per person (0.74). In addition, the 2-unit donors maintained a low homologous transfusion rate of 16%. These data suggest that 2 units of autologous blood donation has a reduced risk of homologous blood transfusion while the amount of autologous blood wasted is minimized.