Dynamic surface tension data for the mixture water + 1-octanol and water + 2-ethyl-1-hexanol with an alcohol mass fraction between 1.6.10(-5) and 10(-3) at (20, 40, and 60) degrees C were measured. The age of the surface was varied between (0.005 and 50) s. A correlation of the data is given. It has been found that the surface tension of water + 2-ethyl-1-hexanol relaxes faster with respect to time than the surface tension of water + 1-octanol. The results are discussed with respect to the use in absorption chillers.