The electrodeposition of tin in a methanesulfonic acid-based plating solution was studied. The effects of agitation, current density, and temperature on the plating efficiency and coating morphology were examined using a rotating cylinder cathode and a rotating disk electrode. A good correlation was found between the plating efficiency and coating morphology; moreover, both of them were affected by the diffusion-limited current density (i(L)) of the stannous ion. A compact crystalline deposit was obtained with >95% plating efficiency at current densities up to i(L) in this plating bath. When the current density exceeds i(L), not only does the plating efficiency begin to decrease but also the coating changes to micronodular and then to dendritic. Through the determination of the temperature dependence of the viscosity of the bath and the diffusion coefficient of the stannous ion, the synergistic effects of temperature and agitation on it were quantified.