A two-dimensional model that describes the strain hardening behavior of dislocation cell-forming crystalline materials at large strains was recently extended to the three-dimensional case In the present study, the deformation behavior of IF steel during equal channel angular pressing (ECAP) was calculated on the basis of the 3D version of the model. The variation of grain orientations in the course of deformation was also taken into account in an analysis based on full constraint Taylor approach. FEM simulations of the behavior of IF steel under ECAP for several passes of pressing in the route A regime are in good agreement with experiment. This refers to both strain hardening and texture. A rapid increase of stress in the first pressing, followed by a drop in strain hardening rate in subsequent pressings, was reproduced well Calculations showed a non-uniform strain distribution in a workpiece. Due to strain non-uniformity, the texture of the lower part of the workpiece was different from that of the middle part. Though the texture components characteristic of the ideal shear deformation were developed, the highest peaks showed deviations from those of the ideal shear deformation. This is attributed to an interplay between plane strain and shear strain under ECAP conditions. It was found that the stable texture of IF steel subjected to ECAP (route A) is {145}<321>.