The atomizing performance of an aerated-liquid atomizer operating under conditions of bubbly flow is investigated. The device tested consists of a plain-orifice atomizer with provision for injecting air or gas through a porous tube into a flowing liquid stream. Measurements of mean drop size and drop-size distribution are made using a light diffraction technique. Water injection pressures are varied from 173 to 690 kPa (25 to 100 psid) and gas/liquid ratios from 0.001 to 0.05 by mass. The results obtained show that good atomization can be achieved using only small amounts of atomizing gas at injection pressures as low as 173 kPa (25 psid). Moreover, atomization quality appears to be largely independent of the size of the nozzle discharge orifice. However, the bubbly flow mechanism of atomization is limited to low gas/liquid mass ratios, the actual value depending on the injection pressure. High injection pressures permit high values of air/liquid ratio.