Mass transfer has been studied at rotating cylinder electrodes of woven-wire meshes using the reduction of ferricyanide as test reaction. The experimental data are well correlated by an empirical expression between the Sherwood number and the Reynolds number, both in terms of the hydraulic diameter as characteristic length, and including two additional dimensionless parameters in order to characterize the geometry of the meshes. The mass-transfer enhancement factor for three-dimensional electrodes is analyzed.