Background: Analysing cost data with respect to savings of red blood cells (rbc) by acute normovolaemic haemodilution (ANH) / hypervolaemic haemodilution (HHD) versus purchasing homologous packed rbc (HPRBC). Methods: Using our previously published model for ANH/HHD we calculated saving of rbc mass for various initial (45 and 40%) and minimal (haematocrit) hct levels (27, 24, 21 and 18%). ANH was performed by isovolaemic exchange of 4 units of blood (each 500 ml) versus colloid with an intravascular volume effect of 1.0. Intra-operative loss of colloid was only due to surgical blood loss. ANH units were re-transfused in reverse order; thereby maintaining isovolaemia and minimal hct level with ongoing blood loss by additional infusion of colloid. HHD was performed by pre-operative infusion of 1,000 ml colloid; assumed intravascular volume effect is 1.0. Hypervolaemia during surgical blood loss was maintained by infusion of colloid until reaching minimal hct. Elimination of the excessive colloid from the intravascular space lead to rise in hct (from minimal to final hct). This difference between final and minimal hct results in saving of rbc mass. Cost data refer to both hospital variable/acquisition cost and data given in DKG-NT (variable/acquisition cost (‘Sachkosten’) and total cost (‘Gesamtkosten’)). Results: ANH at best allows for rbc mass savings of approximately 2 units (each 190 ml of rbc). Under less ideal conditions (initial hct ≤ 40%, minimal hct ≥ 21%), rbc savings amount to approximately 1 unit. With HHD, the corresponding rbc mass saved amounts up to 1 unit at best. Our cost-minimising analysis (CMA) shows that these rbc savings by ANH/HHD are less expensive than purchasing equal amounts of allogeneic rbc mass. With respect to the underlying cost base, these 2 units are between 25% (total cost according to DKG-NT: ANH EUR 166.5 versus HPRBC EUR 221.1) and 60% (hospital variable cost: ANH EUR 61.7 versus HPRBC EUR 157.2) cheaper than corresponding units of HPRBC. rbc mass saved by HHD is even less expensive (total cost according to DKG-NT: HHD EUR 63.8 versus HPRBC EUR 135.1; hospital variable cost EUR 32.1 versus HPRBC EUR 95.2). Thus, they are approximately 53% (total cost according to DKG-NT) to 62% (hospital variable cost) less expensive than HPRBC. Conclusions: Both ANH and HHD – under ideal conditions and within their limited extent – are more cost-effective in saving rbc than transfusion of allogeneic blood. However, both the efficacy of these measures and the resulting financial savings are limited at best to 2 units of rbc for ANH and 1 unit for HHD.