Lactic acid can be made by fermentation from inexpensive cheese whey. The acid is at present fairly costly, however, partly because of the costs of recovery and purification of the acid from the fementation broths. The present study has been undertaken to investigate a process that might reduce these costs. A number of commercial resins have been evaluated as ion exchangers for the production of lactic acid solutions. Amberlite IR-120, a gel strong cationic ion exchanger, was found to be the best resin. The loaded resin was regenerated efficiently. The results suggest that such a process is both technically and economically feasible.