A nebulizer comprising: a housing having an ambient air inlet and a chamber for holding an aerosol an air outlet communicating with the chamber for permitting the aerosol to be withdrawn from the chamber a pressurized gas inlet adjacent a fluid orifice, the pressurized gas inlet in communication with the chamber a diverter positioned in the chamber in a position relative to the pressurized gas inlet and, wherein the relative position of at least one portion of the fluid orifice and the diverter is adjustable between a nebulizing position and a non-nebulizing position, and further comprising a selection means to be manually operated to allow the nebulizer (710) to operate in a breath actuated mode or a continuous nebulization mode.
