 The study shows that periodic arrays of nanorods made of magneto-optical dialectrics can present a resonant response at specific geometric conditions, which can be tuned to obtain a complex interplay between the geometric resonances of the grating and the magneto-optical co-effects, MOC, response. This could lead to new perspectives in sensing applications and optimizing MOC structures and devices based on resonant sub-wavelength gratings. This article was authored by H. Morincio, Akamanati, Agassia Martin, and others.