This research work is devoted to the development of a finite element model for the simulation of the flow of polymer melts through the metering zone of single screw extruders. The sets of the governing equations (flow and energy) were solved using the continuous penalty scheme and a streamline upwinding Petrov-Galerkin method, respectively. The non-Newtonian rheological behavior of the fluid was also taken into account by the use of the power-law model. The novelty of this work is the application of this model on the flow of a polypropylene melt through the helical geometry of a single screw extruder To validate this model, the results of the computer simulations were compared with experimentally measured mass flow rate and also results from a previous model, which was based on the simulation of the flow in a flat flow domain. Comparisons showed that not only there are very good agreements between the model predictions and actual data but also inclusion of the curvature of the screw flights has an important influence on the accuracy of the results.