The paper shows the results of computer modeling of the polymer injection molding process. The influence of the gating system design on the warpage and volumetric shrinkage of the molded part was investigated. Particular attention was paid to the location of the gate. It has been proven that the selection of the place where the material is brought to the molding cavity has a significant impact on the final shape and quality of the molded part. The degree of compliance of its shape with the assumptions and dimensional accuracy was adopted as the criteria for assessing the quality of the molded part. The specialized software package Autodesk Moldflow Insight was used for numerical calculations. The obtained modeling results were related to the design recommendations of gating systems known from the literature.