The limited colloidal stability of alkyd emulsions compared to that of organic solvent-borne alkyd paints is a well known problem. For environmental reasons, however, they have a great advantage since they are water-borne. In this study, we have investigated the influence of emulsifier and initial droplet size on the mechanical stability of alkyd emulsions. Anionic emulsifiers have previously been shown to be more effective than nonionic emulsifiers in the formation of alkyd emulsions. Here it has been found that an anionic emulsifier also gave more stable emulsions at lower concentrations than did the nonionics. Emulsions stabilized with a nonionic emulsifier showed the same stability as the one with the anionic emulsifiers if the concentration was increased. Too high a concentration of surfactants is undesirable in paints, however, since it increases the water sensitivity of the paint film. The mechanical stability of anionically stabilized emulsions was less sensitive to the initial droplet size compared to emulsions stabilized with a nonionic emulsifier.