Abstract Biaxially oriented PE films were prepared by compression of uniaxially oriented elongational-flow injection-molded precursors. The films so prepared, having different extents of biaxial stretching were compared on the basis of two derived functions, biaxial draw ratio (ƛ) and degree of biaxiality (B). The former gives a quantitative measure of the average draw ratio of the film surface. The latter describes the strain distribution along the principal directions of the film plane. It is shown that ƛ and B depend on the final applied pressure and on the type of pressing surfaces used. The dependence of ƛ and B on the initial orientation and on the initial anisometry of the precursors is also discussed in the light of structural arguments.