A device and a method for preventing the drying of fluid products in a delivery head of a machine for dispensing fluid products, wherein the delivery head is provided with a plurality of delivery nozzles. The device comprises first elements to generate a conditioning flow, second elements to convey the conditioning flow towards a space underneath the delivery nozzles and create in said space an atmosphere different from that of the environment in which the dispensing machine is to be found during use. The delivery nozzles are divided into at least two groups and the space is divided into at least two distinct conditioning zones, disposed in correspondence with the groups of delivery nozzles. Different atmospheres are created in the conditioning zones, according to the type of fluid product delivered by the corresponding group of delivery nozzles.