The main objective of this paper is to investigate the potential and effectiveness of direct oil cooling of a PMSM. The lumped parameters thermal network (LPTN), the thermostatic FEM model, and Computational Fluid Dynamics (CFD) model are built. The results of modeling are compared. The pros and cons of each modeling technique are briefly discussed. The detailed flow modeling by means of CFD allows precise determination of the cooling possibilities which gives to designer the information required for choosing the optimal volumetric coolant flow.