The flow of a low-density polyethylene in a flat die is simulated using the axisymmetric and planar elongational viscosities estimated in an earlier publication by Beaupre and Gupta. Elongational viscosity is found to have only a limited effect on the velocity distribution at the die exit. However the predicted pressure drop in the die and the temperature distribution at the die exit changed significantly when the effect of elongational viscosity was included in the simulation.