Permanent magnet synchronous motors (PMSMs) have recently gained increasing industrial and research interest. The PMSM design and especially its performance evaluation through two-dimensional (2D) and three-dimensional (3D) magnetic field analysis using finite element method (FEM) is not trivial, as it is a quite demanding and time consuming procedure. Furthermore, there has always been doubt on the accuracy of 2D analysis results and on which type of analysis is the most preferable one for the specific motor. This work aims to emphasize the difficulties and the advantages that arise from the 3D analysis. The aforementioned simulations were performed for the case of a four-pole PMSM. Several magnetic and electromechanical quantities have been determined. Additionally, various materials were utilized for the construction of stator and rotor cores and their effect on the motor’s behavior was investigated. Finally, the derived results are compared and useful conclusions regarding the solution accuracy are given.