Methionine production by a mutant strain of Corynebacterium Whim was studied at different dilution rates and different dissolved oxygen concentrations, based on a statistical central composite design. The effect of dissolved oxygen levels between 2% and 60% and dilution rate levels between 0.04 to 0.29 on continuous production of methionine was studied. The process is described by the Leudeking-Piret model. The experimentally obtained maxima for methionine and biomass productivities, observed at the same dilution rate of 0.17 h(-1), also corresponds to the theoretical prediction based on this model. This experimental observation is further supported by the surface response prediction of a dilution rate of 0.16 h(-1) for maximum methionine productivity and 0.15 h(-1) for cell mass productivity. Also, beyond the critical value of 30% dissolved oxygen, the apparent benefits of oxygen transfer become less significant.