Accurate experimental determination of the aqueous solubility of 4-position substituted benzoic acid compounds in a high-temperature solution and its correlation are presented. The temperature effect dependence of aqueous solubility was investigated in the range from 303.15 to 473.15 K. The solubility prediction is essential for rapid design and optimization of separation, purification and formulation processes in the chemical industry. Solubility data were determined using a simple and reliable apparatus and analyzed by the classical titration method. Experimental data were regressed with the modified Apelblat equation and the lambda H equation. The lambda H equation gave good agreement with all experimental data. A solubility model modified from the lambda H equation was used to correlate the experimental data. The percentage of average relative deviations of these correlations was 1.40% for the solubility of 4-acetylbenzoic acid in an aqueous solution. (c) 2012 Elsevier B.V. All rights reserved.