The solubilisation constants (K-s) of 4-chlorobenzoic acid in aqueous solutions of various pure and mixed surfactants are determined by the UV-Vis spectrophotometric method. And the dependence of the K-s values on temperature has been measured and thermodynamic parameters are calculated to analyse the effects of head-and tail-groups on the solubilisation of 4-chlorobenzoic acid by various surfactants. The results show that the Delta G(o) values for all the surfactants are negative and decrease with the increase of temperature. On the other hand, the values of Delta H-o and Delta S-o are all positive within the measured temperature range and those values increase together with the increase of temperature. These thermodynamic parameters are depending severely on a chain length of alkyl-group as much as on a head-group of surfactant. (C) 2016 Elsevier Ltd.