The relationship between strain and anisotropy of magnetic susceptibility (AMS) has been investigated in the Carboniferous Flamanville granite in the Armorican Massif, NW France. We measured the axial ratios of elliptical inclusions and the orientation of cleavage planes at eight sites around the granite margin. Measurements of AMS were made on 73 specimens using a Schonstedt spinner magnetometer. AMS measurements are shown to provide accurate predictions of cleavage and lineation direction, even where these structures are difficult to measure in the field. The strain and AMS ellipsoids show similar regional variations in shape and intensity, and a good correlation between the lengths of the principal axes. Finally, our data are consistent with the hypothesis that the Flamanville granite was syntectonically emplaced during the late stages of the Hercynian Orogeny.