8.1 IntroductionNuclear resonant scattering of synchrotron radiation has become an established field of condensed-matter research over the past 25 years. Synchrotron radiation with its outstanding brilliance, transverse coherence, and polarization has opened the field for many unique studies, for fundamental research in the field of lightmatter interaction as well as for materials science. This applies, in particular, to the electronic and magnetic structure of very small sample volumes such as micro-and nanostructures and samples under extreme conditions of pressure and temperature. This chapter is devoted to the application of the technique to nanomagnetic systems such as thin films and multilayers. After a basic introduction