In this paper, the process of modelling and identification of a hydraulic actuator is discussed. In this framework a simple model based on the classical theory has been derived and a first experimental campaign has been performed on a test bench. These tests highlighted the presence of unmodeled phenomena (e.g. dead-zone, hysteresis, etc.), therefore a second and more extensive experimental campaign has been done. With the acquired knowledge an improved model has been developed and its parameters identified. Finally several experimental tests have been performed in order to validate the model.