The combination of Y and Zn as alloying addition is an effective way to improve the property profile of Mg. In addition to structural applications, these types of alloys can be used as temporary implants due to their biocompatibility and degradation under physiological conditions. In situ synchrotron radiation diffraction was performed during tension and compression of an extruded Mg–2Y–1Zn–1Mn alloy at room temperature, at 200 °C and at 350 °C, respectively, up to a deformation of 0.3 with a deformation rate of 10^–3 s⁻¹. The results enable to identify at different temperatures whether crystallographic slip, twinning, and dynamic recrystallization take place to accommodate strain, and which one of those has the dominant role during different stages of deformation. Furthermore, the asymmetry between tensile and compression load is evaluated as an important factor for the further processing of the material.