The effect of n-alkylammonium chloride surfactants on the stability of concentrated oil-in-water emulsions has been investigated as a function of the surfactant chain length. Surfactants with longer hydrocarbon chains were found to form droplets with smaller sizes and to enhance the emulsion stability. An additional increase in the stability of the oil-in-water concentrated emulsions was achieved by using poly(oxyethylene) with M-W = 10000.