Polymer foams with complex cross-sectional shapes are used in a multitude of different applications (including transportation, construction, packaging, food, extraction and separation) thanks to their low mass allowing efficient energy transport, optimal acoustic absorption, catalytic, impact, and cushioning properties [1]. Dimensional accuracy of the final foamed product, obtained through a die, is one of the biggest challenges for the engineering of a stable foam extrusion process. Nowadays, the design of dies is considered an art and, usually, it involves several experimental runs, wherein a die with an approximate shape is manufactured and iteratively modified based on the quality of the extrudate [2]. This method is time and money consuming [3]. Herein, we present an innovative approach that separates two important functions of a die for foams: achievement of a fast pressure drop (i.e. important for triggering the foaming) and uniform exit velocity profile at the exit section (i.e. important for controlling the profile geometry). Our approach allows to simplify the die design by partitioning in two zones, each one linked to a function. The design is tackled using Computational Fluids Dynamics (CFD) reducing the trial-and-error process. We will present the modelling of the rheological behaviour of starch-based mixtures and the results of the CFD simulations on several die geometries that were designed using the innovative approach. [1] S.T. Lee, C.B. Park, Foam Extrusion: Principles and Practice, CRC Press, 2014. [2] Kostic, Milivoje M., and Louis G. Reifschneider. "Design of extrusion dies." Encyclopedia of chemical processing 10 (2006): 633-649. [3] Carneiro, O. S., Nóbrega, J. M., Pinho, F. T., & Oliveira, P. J. (2001). Computer aided rheological design of extrusion dies for profiles. Journal of materials processing technology, 114(1), 75-86.