This study aims to explore the effect of changing the substrate type on the performance of a microstrip patch antenna, in terms of gain, directivity, bandwidth, and bandwidth efficiency. Three different substrates were investigated: Rogers RT5880, FR-4, and Alumina. Each substrate has distinct physical and electrical properties, which influence the antenna’s performance and overall dimensions. The design and simulation were carried out using CST Microwave Studio, where a simple microstrip patch antenna operating at 2.4 GHz was modelled. The performance for each substrate was analyzed, and the simulation results were discussed. The results highlighted clear differences in performance among the three substrates. Rogers RT5880 demonstrated the best performance in terms of gain and radiation efficiency, while FR-4 was the most cost-effective, albeit less efficient. On the other hand, Alumina exhibited a very compact size due to its high dielectric permittivity, but faced challenges related to material losses................. Keywords:.......... Microstrip Patch Antenna, Rogers RT5880, FR-4, Alumina, CST Microwave Studio.