Abstract The problem of mass transfer during anodic dissolution of vertical wire tungsten electrode in the alkaline solution under the conditions of natural convection is solved numerically. The concentration dependences of ionic diffusion coefficients, solution density and viscosity are taken into account. The distributions of concentrations, current density and potential over the near-anode layer are determined. The dependence of limiting current on the concentration of alkaline solution is obtained. The role of ion migration in the tungsten dissolution is shown. The results are compared with the experimental data.