Low-molecular-weight carboxylic acids (C-2 to C-6) and phenols have been isolated from water solutions by vapor phase extraction (VPE). The influence of the molecular structure and the extractant type on the extraction efficiency has been investigated. The suggested model mechanism of VPE is in good agreement with the experimental results and allows quantitative calculations of the changes of Gibbs free energy as a function of the. molecular length for the above carbonic acids and of polarity for cresol isomers.