The blends of high-density polyethylene (HDPE) with atactic polystyrene (PS) were deformed plastically by plane-strain compression in a channel die. The samples were deformed up to the true strain 1.8 (compression ratio 6) in three temperature regimes : below, near, and above the glass transition temperature of polystyrene component. The morphology and the texture of crystalline component in the deformed blend samples were investigated by means of scanning electron microscopy and wide angle X-ray diffraction (pole figures technique). It was found that the deformation process in the blend of immiscible HDPE and PS does not differ markedly from the deformation of the one-component system from the point of view of the deformation mechanisms involved. The crystalline textures of the blend samples are qualitatively the same as in the plain HDPE deformed under similar conditions. The active deformation mechanisms are the same in deformation of both the plain HDPE and HDPE/PS blend, The mechanism identified are crystallographic slips : (100)[001], (100)[010], and (010[001] supported by the interlamellar slip. The presence of PS in blends modifies to some extent the deformation process and resulting orientation of the crystalline component, of HDPE by modification of the stress distribution within HDPE matrix around PS inclusions. This influence is much stronger at low deformation temperatures, when PS is in a glassy state, than at temperatures above T-g of PS.