Surface tension of aqueous solutions of aliphatic esters (methyl, ethyl, propyl, and butyl acetate) were determined at a temperature of 298.15 K and atmospheric pressure over the mole fraction range reaching the solubility limit in the aqueous phase. The discussion of results examines the influence of the size of the ester hydrocarbon chain on the surface tension. Experimental results have been analyzed using the Langmuir model, and the ability of the Langmuir equation to describe the concentration dependence of surface tension has been tested.