The effect of microstructure and texture on the flow stress anisotropy in aluminium and IF steel has been investigated. The samples are recrystallized commercial purity aluminium (AA1050) cold rolled to prestrains of 0.05, 0.11 and 0.2, and recrystallized IF steel cold rolled to a prestrain of 0.28. The flow stress anisotropy was measured by tensile testing of specimens cut along different directions in the rolling plane. Pronounced anisotropy was found in both materials in spite of weak textures. The yield stress increases with increasing angle between the tensile direction and the rolling direction at all prestrains. The effect of microstructure and texture on the flow stress anisotropy was modelled by incorporating into a full-constraint Taylor model the strengthening effect of dislocation boundaries. The modelling and experimental results agree well, leading to a discussion of effect of the microstructure and texture on the flow stress anisotropy.