A method is for inactivating xenoantigens in biological tissues, particularly in tissues that can be used to manufacture bioprosthetic substitutes and/or in bioprosthetic substitutes that are already prepared and intended for human or veterinary clinical use. The method entails the following steps: providing a solution based on phenolic compounds, polyphenolic compounds or derivatives thereof, for the inactivation of at least part of the xenogeneic epitopes from such tissues incubating the samples to be treated in the various solutions based on phenols/polyphenols in controlled conditions and subjecting the treated tissues to a series of washes.
