The perioperative course of 118 patients weighing less than 45.5 kg (100.1 pounds) who participated in a predeposited autologous blood program from 1979-1984 is reviewed. Average age was 13 years 11 months (range 6 years 4 months to 20 years 4 months) and the average weight, 41 kg (range 30-45.4 kg). All underwent spinal surgery, 96% for scoliosis. The program involved preoperative donation of blood that was stored and subsequently retransfused to replace operative blood losses. Patients donated an average of 811 ml (range 208-1,320 ml) blood. Operation and hospitalization were completed by 63% without receiving any homologous blood, and the need for donor blood was reduced in the remaining 37%. Preoperative blood donation and retransfusion led to no significant complications. We describe an autologous blood transfusion program and show that autotransfusion is a safe and preferred method of blood replacement for children and young adults with low body weight undergoing elective surgery.