Abstract: The invention relates to a process for the manufacture of very high-purity antihemophilic factor (FVIIIc) and von Willebrand factor. This process enables the manufacture of very high-purity antihemophilic factor (FIIIc) devoid of the bulk of the Willebrand factor comprises a step for purification by ion exchange chromatography with the aid of a chromatography column containing a gel, the purification step comprising a step for adsorption of the antihemophilic factor essentially devoid of the Willebrand factor on the gel in the column and a step for desorption of the purified antihemophilic factor, which is collected, thereby obtaining an antihemophilic factor devoid of the bulk of the Willebrand factor and having an activity as high as 250 IU/mg of proteins. This process also permits to recover von Willebrand factor in very high purity.