A drop volume tensiometer was employed to measure the surface tensions for the binary mixtures of each of the isomers of chlorobutane with each of the isomers of butanol at a temperature of 298.15 K. From these data the surface tension deviations were calculated. The results have been compared with the predictions obtained by the group contribution method proposed by Suarez. (C) 2004 Elsevier Inc. All rights reserved.