This article presents a procedure to achieve a uniform outlet flow of molten polymer for a complex die profile with various thicknesses in die outlet cross section. According to a specific optimization methodology, the die was optimized based on varying die land length. The scope of this article includes: 3D flow simulation, optimization of the die velocity outputs based on the results of simulation process, and comparison of numerical predictions with the experimental data. Finally a significant result obtained by this work indicates higher ratio of the land length to the height of the zone with cross flow rather than the zones that are directly fed by the extruder. POLYM. ENG. SCI., 50:2417-2424, 2010. (C) 2010 Society of Plastics Engineers