The oxidation of benzoic acid (BA) to phenol (the Dow Phenol Process) has been studied in high temperature water (HTW) using a continuous flow system over various metal oxide heterogeneous catalysts: NiO, CuO, Carulite (R), MnO2 and Al2O3. Excellent selectivities (> 99%) and good yields for phenol (up to 70%) were obtained. The reaction conditions were optimised by varying the temperature, the pressure and the effect Of O-2. Experiments were carried out for sustained periods in order to study the catalyst deactivation. The results are presented in most of the cases in dynamic conditions; results observed versus time-on-stream for each catalyst tested. Carulite (R) 300 catalyst was the most effective with a good activity/robustness over time-on-stream. Activity and regeneration of the catalyst with oxygen is reported. Overall HTW shows considerable potential as a medium for this process. Possibilities for extending this chemistry are discussed. (c) 2006 Elsevier B.V. All rights reserved.