The invention relates to a method and an apparatus for optimizing an extracorporeal blood treatment using an extracorporeal blood treatment apparatus, comprising a dialyzer (1) or filter, which is divided into a first chamber (3) and a second chamber (4) by a semipermeable membrane (2), the first chamber being part of an extracorporeal blood circulation I and the second chamber of the dialyzer or filter being part of a dialysis fluid system II. Furthermore, the invention relates to an extracorporeal blood treatment apparatus with a device for optimizing the extracorporeal blood treatment and to a computer programme product to be executed on a data processing installation for carrying out a method for optimizing the extracorporeal blood treatment. The method and apparatus according to the invention are characterized in that at least one machine-specific treatment parameter for carrying out the treatment using the respective dialyzer or filter is determined with a computing unit for different types of dialyzers or filters. The computing unit allows determining the costs resulting from the determined machine-specific treatment parameters when using the respective dialyzer or filter. The determined costs for all types of dialyzers or filters are then displayed on a display unit. In this way, the information required for selecting the dialyzer or filter is provided to the treating doctor. The doctor can then select the dialyzer or filter in order to keep the costs of the blood treatment as low as possible.
