Power consumption in a cylindrical mixing vessel with a spherical bottom was investigated over a wide range of Reynolds number. A paddle and a turbine were used as radial flow impellers, and a pitched paddle and a propeller as axial flow impellers. In unbaffled cylindrical mixing vessels, power consumption in a spherical-bottomed vessel was equal to that in a flat-bottomed vessel. In baffled cylindrical mixing vessels with radial flow impellers, power consumption in a spherical-bottomed vessel was smaller than that in a flat-bottomed vessel in the transition and turbulent flow regions, but no difference due to bottom shape found in baffled vessels with axial flow impellers. The power consumption in spherical-bottomed cylindrical mixing vessels was correlated by using baffle plate length as a parameter.