Gas dispersion characteristics of a single impeller in a fully baffled cylindrical pilot scale stirred vessel (T = 0.72 m) were studied for newly developed impellers, which are a 6-bladed hollow blade disc turbine (6HB) and a Lightnin A315 (A315), in addition to the traditional 6-bladed Rushton disc turbine (6DT), under unarerated and aerated conditions in water. The power drawn, gas hold-up and k(L)a (oxygen mass transfer rate) obtained were compared with those for the 6DT reported in literature. As a result, it was found that the gas handling capacities of the 6HB and A315 are superior to that of the 6DT.