We applied the electrochemical atomic layer epitaxy (ECALE) methodology to obtain deposits of CdS and ZnS on Ag(111) by alternate underpotential deposition of the elements forming the compounds. The amounts of the elements deposited, determined by stripping coulometry, always yielded a stoichiometric 1:1 ratio. The deposits were formed using an automated electrochemical deposition system, described here, making use of a simple distribution valve.