Objective: In recent years blood transfusion has become a debated health care issue. To minimise exposure to infectious agents and reduce bank blood transfusion requirements, leucocyte filtration and perioperative red cell salvage (RCS) are increasingly used in paediatric patients. We hypothesised RCS would reduce the need for additional blood products in children following cardiopulmonary bypass (CPB). Methods: Patients undergoing routine or emergency cardiac surgery requiring CPB over a study period of 3 months were included prospectively in the analysis. Haemoglobin, platelet count, coagulation screen and heparin levels were performed before, immediately after surgery and 24 hours later. RCS was performed in theatre according to surgical and anaesthetic preference. Red cells were salvaged from the surgical site, anticoagulated, washed and following resuspension in saline reinfused into the patient within 4 hours. The incidence of post-operative bleeding (>10 ml/kg/hr) was recorded, as was the need for additional red blood cells, platelets and fresh frozen plasma (FFP). The need for blood products was at the discretion of the consultant intensivist. Statistical analysis was performed using student t-test and Chi squared methods. Significance was accepted as p < 0.05. Results: Thirty-five consecutive patients (34.54 ± 43.55 months, 13.48 ± 14.39 kg) were included in the analysis. A total of 17 infants <12 months were included, 9/24 who received RCS and 8/11 who did not (p 0.052). Cyanotic heart disease was seen in 40%. RCS was performed in 24 of 35 patients, who were significantly older (44.2 ± 44.1 vs. 13.6 ± 25.5, p 0.02) and heavier (16.6 ± 16.2 vs. 6.7 ± 4.7, p 0.01). No difference was seen in the prevalence of cyanosis between the two groups. Post-operative bleeding was seen in 21% who underwent RCS and 40% in those who did not (p 0.33). The need for additional red blood cells was significantly reduced in those who received RCS, 37.5% vs. 91%, p 0.003, as was the use of FFP, 8.3% vs. 45.5%, p 0.02. There was no difference in the need for platelet transfusion, p 0.2. Discussion: In this study RCS was performed on 68.5% of children following CPB. RCS significantly reduced the need for further blood and FFP transfusion, although this was not related to post-operative bleeding. This has important implications for both exposure to infectious agents and health economics. That children who underwent RCS were older and heavier may be related to the complexity of surgery and CPB in younger patients, although infants were represented in both groups. A further analysis of potential health and economic benefits in a homogenous group is needed.