Awareness of the potential for transmission of the spread of viral diseases through homologous blood products has led to an increasing awareness of techniques that minimize these risks. Reinfusion of postoperatively shed blood has become popular, but its efficacy has been questioned. In an effort to determine the viability of postoperatively collected cells, 10 consecutive patients undergoing an identical surgical procedure were studied; their blood was tagged with chromium 51 and reinfused. Reinfused cells were then monitored serially at determined intervals and expressed as a percentage of postinfusion activity. At 4 days, 75.9% of initial activity remained. These figures are comparable to those previously reported for intraoperative and preoperative cell collection. Blood salvaged postoperatively is not significantly damaged and is as viable as blood collected from other autologous and homologous sources.