Method for controlling a piezoelectric actuator acting on valve elements to open or close a fuel injector respectively allowing or preventing fuel injection into a combustion chamber of an engine, the method includes: applying to the piezoelectric actuator a nominal electrical charge to open the injector, as a function of the torque required and the engine speed, to open the valve elements for fuel injection, thereafter applying to the actuator at least one electrical polarization charge, to polarize the actuator during an opening phase of the injector and fuel injection into the combustion chamber, thereafter commanding the closure of the injector by applying to the actuator at least one electrical discharge to close the valve elements, the step of applying the electrical polarization charge including a prior step of increasing the value of the charge current to a value greater than that of the nominal charge.