Abstract: This paper presents a study of the effect of inorganic electrolytes on the rate of coalescence of organic droplets in an aqueous continuous phase. It was found that the addition of ionizing salts to the aqueous phase resulted in an increase in coalescence time at a flat interface with droplets of polar organic liquids, such as butyl acetate. In contrast, no change in coalescence time was observed for non-polar droplets such as heptane. These results are discussed in relation to existing theories of drop coalescence, and a qualitative explanation of the phenomenon is proposed in terms oi an increase in the intertacial viscosity.