A method of driving a hydraulic actuator provided with a pressure-controlled proportioning solenoid valve; the method includes the steps of: determining a first open-loop contribution according to a pressurized oil flow rate which crosses the proportioning solenoid valve and according to the desired load pressure inside the actuation chamber; determining a second open-loop contribution according to the desired position of the spool of the proportioning solenoid valve; determining a third closed-loop contribution according to the difference between a desired value of the position of the mobile piston and a real value of the position of the mobile piston; and calculating a desired electric driving current value of the proportioning solenoid valve by means of an algebraic sum of the three contributions.