The effect of hydrodynamic conditions and physical properties on the characteristics of an emulsion dispersion in a stirred tank was studied in the presence of mass transfer, in an attempt to identify the parameters for Sauter mean diameter data correlation in emulsion liquid membranes. The organic phase of the water-in-oil emulsion contained the cadmium extractant Cyanex 302 and an emulsion stabilizer, and the dispersion continuous phase was an aqueous solution of phosphoric acid containing cadmium. Variations in emulsion viscosity and interfacial tension were achieved by changing the extractant and surfactant concentrations. The dispersion drop size distribution was measured from photographs taken with a high-speed video camera system attached to an endoscope. It was found that the emulsion physical properties, emulsion swelling, and operating conditions were interrelated in a complex way. However, emulsion swelling seemed to lump together the effect of some of the parameters on globule size, which made possible the development of a simple correlation for the Sauter mean diameter in terms of We(-0.6), emulsion swelling percentage, and empirical correction factors for emulsion viscosity and dispersed-phase holdup. A modified Rosin-Rammler probability distribution function fitted well the globule size distribution data.