Critical Evaluation of Some Equilibrium Constants Involving Organophosphorus Extractants is a supplementary text to the compilation "e;Equilibrium Constants of Liquid-Liquid Distribution Reactions (Introduction, and Part I: Organophosphorus Extractants). The book contains a number of well documented chemical reactions that are critically evaluated. The reactions evaluated comprise those from List 1 for which data are available. There are, however, a great variety of reactions that cannot be critically evaluated due to lack of experimental data and unverifiable results. Chemists will find this compendium very useful.