Volunteer shoppers purchased antiglaucoma medications dispensed from prescriptions written according to generic and brand-name products in Manhattan and in the St. Louis area. All drugs obtained were more expensive in Manhattan than in St. Louis. No significant cost difference was found between generic and brand-name items in either city, but only in a few instances were generic drugs actually dispensed. No difference in overall price was found between pharmacies located in better and poorer neighborhoods in Manhattan or between pharmacies located in urban, suburban, or rural areas in St. Louis. A white shopper paid significantly lower retail prices than did a Hispanic shopper in Manhattan, particularly in better neighborhoods. The range of prices in each city for all drugs studied was greater than twofold. Pharmacies offering more patient services tended to charge higher prices, but frequently, pharmacies did not actually offer the services they advertised.