The anodic dissolution of tungsten in the alkaline solutions is a widely used process that forms the basis for electrochemical polishing and electrochemical machining of this metal, electrochemical sharpening of a wire for fabrication of scanning probe microscope tips and tools for electrochemical micro/nanomachining. Well reproducible linear dependence of anodic limiting current on the concentration of alkaline solution enables one to use tungsten electrode as a sensor for the content of OH- ions in the concentrated alkaline solutions.  The anodic dissolution of tungsten in the alkaline solutions (KOH or NaOH) with concentrations of approximately 1 mol/L was studied in several works. At low polarizations, the Tafel sections are observed in the anodic polarization curves. At higher anodic potentials, the dissolution rate is controlled by mass transfer in the near-electrode layer, and the limiting current is observed. Many experiments, including the experiments with tungsten rotating disk electrode, led to the conclusion that the diffusion limiting current is associated with the limited rate of delivery of OH- ions that are directly involved in the tungsten dissolution. Tungsten dissolution includes the multi-stage metal oxidation and subsequent chemical reaction.  Based on the analytical solution of the problem of anodic dissolution of metal with the formation of complex with electrolyte anions, the equation for the diffusion limiting current of tungsten anodic dissolution within the framework of the Nernst diffusion layer was presented in [1]. Almost perfect coincidence of the experimental results in relatively concentrated alkaline solutions with the results of very simplified calculations (1) and a considerable difference in relatively dilute solutions lead to the need for a more detailed theoretical analysis of transport processes in this electrochemical system.  The aim of this work is a theoretical analysis of mass transfer during anodic dissolution of tungsten in the alkaline solutions as a practically important process and as an example of anodic dissolution of a metal with the formation of a stable complex of this metal with an anion. In this work, the problem of mass transfer during anodic dissolution of tungsten disk electrode in alkaline solution is solved numerically. The concentration dependences of ionic diffusion coefficients, solution density and viscosity are taken into account. The distributions of concentrations, partial current densities of ions and potential over the layer of solution near the anode 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 and the results of analytical solution of the problem of limiting current available from the literature.