The present invention is relative to an apparatus for dosing and controlling a nebulized spray on an elongated hollow body, in particular for medical or food use. The apparatus comprises at least a valve (2) provided with a nozzle (3) to spray a nebulized substance on the hollow body (7). The valve (2) is supported on a carriage (4) axially movable between an initial inactive position, in which the carriage (4) is located in a rearward position with respect to the hollow body (7), and an operating position in which at least one end portion of the hollow body (7) is substantially aligned with the nozzle (3) so as to be struck by the nebulized spray (19). Occluding means cooperating with the mouth of the hollow body (7) when the carriage (4) is in the operating position are provided to prevent the penetration of particles of the nebulized substance inside the hollow body (7).