System and method for sterilizing a fluid. The system comprises a UV emitter (1) surrounded by an elongated element (2) arranged concentrically with respect to the UV emitter through which a coolant fluid cooling the UV emitter circulates, the elongated element (2) being surrounded by an elongated element (3) arranged concentrically with respect to the UV emitter through which the fluid to be sterilized circulates, the elongated element being (3) surrounded by an elongated element (4) arranged concentrically with respect to the UV emitter through which a coolant or heating fluid cooling or heating the fluid to be sterilized circulates. In the method for sterilizing a fluid, the fluid to be sterilized is subjected to UV radiation at a temperature ranging between -20 º C and 160 º C.
