An embodiment of the present invention is a method of controlling an Organic Rankine Cycle system, the system comprising at least one feed pump (2), at least one heat exchanger (3), an expansion turbine (5) and a condenser (6), the organic Rankine Cycle comprising a feeding phase of an organic working fluid, a heating and vaporization phase of the same working fluid, an expansion and condensation phase of the same working fluid, wherein said method controls an adjusted variable (X), which is a function of an overheating of the organic fluid, by means of a controller (20) that acts by varying a control variable (Y), which is a parameter of the organic fluid in its liquid phase, and wherein the adjusted variable (X) is a temperature difference (ΔT) between a current temperature of the organic fluid in vapor phase at the turbine inlet and a temperature threshold (Tlim), under which the expansion phase involves the formation of a liquid phase of the organic fluid.