Creep behavior of 40- and 80-mu m-thick films of linear low-density polyethylene with four different densities produced by blowing and casting processes was investigated at room temperature (RT) and 70 degrees C. As a criterion for ductile creep failure, strain-to-failure was chosen, which amounts to the maximum elongation characterized by necking of the whole sample. At RT under the stress of 8 MPa, strain-to-failure increases by one order of magnitude (from 0.08 to 0.80) with a decrease in density from 0.930 to 0.902 g/cm(3). Processing effects creep deformation much less significantly in comparison with density. It is found that under loading at RT, some amount of orthorhombic phase in films with the densities of 0.902 and 0.912 g/cm(3) transforms into the monocline phase. The intensity of a peak of this phase near the angle 20 of 19.5 degrees does not depend on the test duration. POLYM. ENG. SCI., 51: 1642-1649, 2011. (C) 2011 Society of Plastics Engineers