Substructure development in polycrystalline magnesium compressed at different temperatures and strain rates was investigated by means of light microscopy, X-ray diffractometry (texture and line-broadening analysis), and in some cases also by TEM or SEM. The fracture of the specimens is accompanied by shear banding. Dynamic recrystallisation starting above RT must be taken into account. The experimental results reflect the interaction between twinning and dislocation slip during the deformation, which leads to significant texture changes. (C) 2002 Elsevier Science B.V. All rights reserved.