The properties of commercially viable Mg alloys are not sufficient for many of the envisaged applications. The combination of Zn and rare earth metals is one of the most effective ways to enhance the mechanical properties of Mg alloys. In situ synchrotron radiation diffraction is a unique method to investigate the dynamic microstructural processes occurring during deformation. Azimuthal angle–time plots give information on grain structure changes that can be correlated with grain rotation, twinning, recovery and recrystallization. As-cast Mg5Nd, Mg5Nd3Zn, Mg5Nd5Zn and Mg5Nd7Zn alloys were investigated during compression at room temperature, at 200, °C and at 350, °C with a strain rate of 10−3, s−1 until 10% deformation. The results and post mortem metallography were compared. At high temperatures grain rotation and sub-grain formation are active to obtain the final texture, while at room temperature twinning is the dominant deformation mechanism.