To achieve high power density in electric motors, the heat exchange system must provide high performance for the removal of heat generated by intrinsic motor losses and limit the temperature rise during motor operation. The focus of this work is the fluid-thermal design optimization of a high-power density electric motor using CFD (Computational Fluid Dynamics) analysis, advanced cooling methods, and experimental results. A motor with rated power of 25 kW, 4 poles and 1700 rpm was used as reference for the fluid-thermal design optimization, which comprises a direct winding heat exchanger. For CFD analysis, commercial software based on Finite Volume Method was used to solve the governing equations for flow and heat transfer in the 3D model of the motor. Additionally, the k-ω SST (Shear Stress Transport) turbulence model was used. The optimization procedure was performed using the Non-dominated Sorting Genetic Algorithm-II (NSGA-II) method based on controlled elitism concepts, focusing on maximizing the heat exchange of the motor cooling system, considering the heat exchange dimensions as input parameters. Through the proposed methodology, it was possible to achieve a significant improvement in the cooling system by decreasing the motor temperature, which allows an increase in motor power. The use of cold plates allowed for an increase in power density of around 60 % and a reduction of pressure drop of around 70 %.