A method for controlling the crystallographic orientation of at least one grain of a turbo engine part. The method includes emitting a beam of electromagnetic radiation through an elementary volume of the part and record diffraction information on the electromagnetic radiation passing through the part. This step is repeated on a given area of the part. The method further includes determining the crystal spatial orientation of each of said elementary volumes and deducing the presence of at least one first crystallographic grain for which the elementary volumes are oriented according to the same crystallographic orientation. The method further includes calculating the angular difference between the crystal spatial orientation of said first grain and a predetermined direction taken from the part and comparing it to a first predetermined threshold value and determining a state of use of the part.