A scaling analysis and an experimental study of mass transfer rate in rotating shallow electrochemical cells are performed. The scaling analysis finds two convection regimes and shows that the parameters Ek and Sc Ro(s) are important to determine the mass transfer rate. The parameter Sc Ro(s) determines the thickness ratio of the viscous layer to the solutal layer as well as the convection regimes. The experimental study on mass transfer rate in rotating cells is conducted by utilizing the limiting current measurements with a cupric sulfate-sulfuric acid system. The overall mass transfer rates measured in the experiment are shown to agree with the scaling analysis and existing heat transfer data.