This thesis is focused on the study and the simulation of a radial pistons hydraulic motor, used for applications where low rotational speed and high torque are needed. This typology can be part of a hydrostatic transmission mounted on vehicles; coupled to the wheels, it can provide traction. Starting from a model kindly donated to the FPRL by Poclain Hydraulics® (identified by catalogue research as a MSE02 Classic), a three-dimensional representation has been done with the aim of obtaining an animation capable to faithfully reproduce the actual kinematics; the software used for this purpose has been SolidWorks®. Then, after the evaluation of some fundamental parameters such as flow areas development, piston chamber volume and its derivative with respect to the angle of rotation, a simulation has been conducted in Amesim® environment.