A device for delivering a substance in the form of aerosol is described. The device is used with a syringe equipped with a plunger and without a needle. The delivery device comprises: a connection sleeve for connecting the device with the syringe； a nozzle for delivering the substance as aerosol, preferably with troncoconical walls and obtained on an elongated outer body of the device； and a fluid-dynamic path comprised between the connection sleeve and the dispensing nozzle, wherein the path comprises an annular expansion chamber and an elongated acceleration chamber, so that, while in use, a manual actuation of the plunger introduces the substance into the fluid-dynamic path in a liquid form through the connection sleeve and produces the substance as aerosol through the dispensing nozzle.
