Abstract: The invention relates to a method for processing fatty wastes leading to a better valorization, particularly for use as fuel. According to the invention, this method is substantially characterized in that it comprises a chemical treatment of fatty wastes (1, 1?), wherein fatty wastes (1, 1?) are mixed with water (8) and an acid-type reagent (7) so as to obtain a demineralized fatty phase not containing mineral elements belonging to the alkaline and alkaline earths families, and an aqueous phase which may include solid residues as precipitates; followed by a mechanical treatment wherein the obtained mixture undergoes a mechanical separation (11) through decanting or filtering, so as to separate the demineralized fatty phase from the aqueous phase.