The aim of this study was to assess blood salvage during Caesarean section. In 15 Caesarean sections, red cells lost were collected and washed with a Dideco machine and tested for the presence of fetoplacental material, bacterial contamination, free haemoglobin and fetal blood cells. Successive patients were allocated randomly to one of two groups. In group 1 (n = 34), intraoperative blood was salvaged, while group 2 served as a control. The mean amount of blood salvaged in group 1 was 363 (SD 153) ml. Blood was salvaged following these guidelines: identification of blood group of the mother and fetus; avoidance of aspirating blood from the umbilical cord; commencement of salvage after removing the fetoplacental unit; completely filling the centrifugation bowl with red cells; washing the cells using at least 1000 ml of physiological solution per bowl; and mixing the contents of the bowl, completely eliminating the buffy coat where fetal cells are located. In group 1, the use of homologous blood transfusions was significantly lower (one of 34 (2.9%) patients compared with eight of 34 (23.5%); P = 0.01), haemoglobin concentrations during the first 4 days after operation were significantly higher and postoperative hospital stay was significantly shorter. Duration of hospital stay was significantly shorter in group 1 (5.3 (1.9) vs 7.3 (4) days; P = 0.003). Mean base haemoglobin concentrations were significantly lower in group 1 (10.7 (1.4) vs 11.7 (1.5) g dl-1; P > 0.0001), while after surgery mean haemoglobin concentrations were significantly higher approximately 3 h after operation compared with the control group (10.2 (1.5) vs 8.6 (1.2) g dl-1; P < 0.0001). On the first day, haemoglobin concentrations were 9.8 (1.5) vs 8 (1.4) g dl-1 (P < 0.0001), on the second day 9.8 (1.4) vs 7.7 (1.4) g dl-1 (P < 0.0001), on the third day 10.1 (1.5) vs 7.5 (1.3) g dl-1 (P < 0.0001) and on the fourth day 10.4 (1.5) vs 8.1 (1.4) g dl-1 (P < 0.0001).