This master thesis deals with the optimization of the number and arrangement of mold cavities for injection molding of rubber compounds. It provides an insight into the types of caoutchouc most often used in the production of elastomers (rubber), types of additives, and types of rubber mixing procedures. This paper lists the most important processing properties and describes the course of the crosslinking reaction of rubber compounds into a rubber product. It gives a description of a cyclic process called injection molding of polymers and a description of a system for injection molding of rubber compounds, consisting of a hydraulic injection press and a mold. A methodical approach to mold development enables its vital elements to be identified, and possible configurations of these elements to be generated. By running a computer simulation of injection molding of rubber compounds, it is possible to monitor the course of all phases and the influence of all processing parameters. All 12 hockey puck mold concepts designed for the purpose of this paper were run through a computer simulation of injection molding. Some concepts have the same amount but different arrangement of mold cavities. The results obtained in the numerical analysis are presented in tabular form, and the key performance indicators of rubber compound processing are presented in graphs. The graphs were generated by comparing the geometric and process characteristics of each concept and were further used to draw a conclusion on the optimal mold configuration for injection molding of hockey pucks. The construction solutions of the mold were developed using the CAD software Solidworks 2020, while the computer simulation of the injection molding of hockey pucks was run using the CAE software Moldex3D Studio 2021.