A cooling device for components of wind turbines, comprising at least one conduit (3) containing therein a working fluid (5) selected to change from a liquid to gas phase, and vice versa, during operation; wherein a first lower portion of each conduit (3) is inserted into a receptacle (2) through which a primary coolant fluid (10) transporting heat from a component of a wind turbine to be cooled (7) circulates, said lower portion acting as an evaporator of the working fluid (5); and wherein a second upper portion of each conduit (3) remains outside the receptacle (2), acting as a condenser of the working fluid (5).