AbstractThe mechanical anisotropy behaviour of the extruded AZ31 magnesium alloy was investigated by in-situ measurements of acoustic emission. Specimens taken in the extrusion direction were uniaxially loaded in tension and compression at room temperature. The acoustic emission count rates were correlated with stress–strain curves and their values show local maxima at the yield point, which is linked with cooperative dislocation processes and/or with the occurrence of deformation twins, especially in compression tests. During compression tests, another acoustic emission maximum occurs after the yield point which indicates the activation of further deformation mechanisms. In this paper the acoustic emission results are presented and discussed in terms of texture evolution during plastic deformation.