The present contribution reports on the characterization of the kinetics of phenol conversion by Pseudomonas. sp. OX1 in a continuously-operated, stirred reactor. The investigation has been carried out in a 2 L reactor, mechanically stirred. The phenol containing solution is delivered at dilution rates (D) varying from 0.025 to 0.5 h. The phenol conversion process has been characterized in terms of time resolved measurements the concentration in the liquid phase of phenol, cells, 2-hydroxymuconic semialdehyde, the oxygen uptake rate, the total organic carbon and the total nitrogen. Data were processed to assess the kinetic models and related parameters – of phenol conversion and cell growth under a wide range of operating conditions, from quasibatch up to values close to the wash-out conditions. The bacterial maintenance was also assessed for growth on phenol. Kinetic parameters and phenol-to-biomass fractional yield coefficient were significantly different from those estimated during batch cultures. The maximum phenol degradation rate was of about 0.5 g/(L h).