Phenylacetic acid extraction from an aqueous system gets consideration because of its extensive uses in the production of beta-lactam antibiotics. In the present paper, reactive extraction has been investigated for the removal of phenylacetic acid by tri-n-butyl phosphate from the aqueous phase in benzene, hexanol, and rice bran oil as diluents. Reactive extraction data were discussed in terms of overall distribution coefficients (D-o), loading ratio (phi), degree of extraction (eta %), and equilibrium complexation constants (E-alpha beta). The mass action law model was used to represent equilibrium of reactive extraction of phenylacetic acid tri-n-butyl phosphate. Also the results on water coextraction have been presented. A further extensive discussion on toxicity, back extraction, and regeneration was given. It is a first kind of study for the removal of phenylacetic acid from the aqueous phase by reactive extraction using tri-n-butyl phosphate in benzene, hexanol, and rice bran oil.