The mechanism of tin cementation by zinc powders in alkaline solution (300 g/l NaOH + 74.7 g/l ZnO + 0.113 g/l SnO) was investigated and the reaction kinetics were characterized under different experimental conditions. Diffusion coefficients of tin in the solution were determined from 35 to 80 degrees C using a rotating disk electrode. Assessment of the experimental results and activation energy of the cementation reaction indicates that the process is controlled by diffusion of tin cations.