Cheese powder is mainly used as a flavor ingredient in food formulations. However, it may act as an emulsifier when added to oil-in-water emulsions, but no systematic investigation of the emulsification properties of cheese powder has previously been reported. Using cheese powders produced with and without addition of emulsifying salts (ES) during powder manufacture, at concentrations of 15, 30 and 45 g/kg (on protein basis), oil-in-water emulsions (20:80 kg/kg) were prepared, stored and assessed for physical stability and flow properties. Emulsions produced using cheese powders containing ES had higher pH and zeta potential, a more Newtonian behavior and improved physical stability compared with cheese powders without ES. The physical stability of emulsions was significantly improved with an increase in protein content. Completely stable emulsions for up to 20 days were obtained with both types of cheese powders using 45 g/kg protein, making it possible to stabilize an emulsion with cheese powder either with or without ES. Thus, it is possible to use cheese powder as a natural emulsifier and thereby eliminate or reduce the need for addition of other emulsifiers.