Measurements of electrochemical potential have been used to evaluate relative inhibitor effectiveness in controlling the corrosion of rebar in chloride-doped simulated pore solution. The rates at which inhibitors bring the corrosion potential into the passive region provide a comparison of inhibitor effectiveness and serve as a screening test. Degreased rebar specimens were immersed in aerated solutions and their electrode potential was measured against a standard calomel electrode over several months. Measurements were made of corrosion potentials as a function of time both in the presence and in the absence of inhibitors and at various inhibitor concentrations. Results of the test procedure are described and comparisons are made with parallel tests of inhibition using visual methods and surface analytical techniques.