The chain originated in Norman, Oklahoma in May 1978. By 1980, Taco Mayo had expanded into franchising by establishing three stores in the Oklahoma City metropolitan area. Over the years, Taco Mayo has expanded from a single store in Norman into a regional operation with franchise locations throughout Oklahoma, northern Texas, southern Kansas, and western Arkansas. The restaurant wanted to expand to 200 locations by the year 2000. While it did not reach that goal, it had reached its hundredth location by 1997. After the “expansion program” failed, the company began realizing its marketing mistake: never force quantity over quality. Many of the restaurants were built and opened in such a rush that the company did not care about finding the right individuals to run the restaurant or finding the right locations to place the restaurants. Not wanting to be the fast-food chain that everyone stereotyped as poorly crafted or run-down, Taco Mayo's corporate offices closed down many of the locations that were functioning poorly. To this day there are fifty-three Taco Mayo locations throughout Oklahoma and its surrounding areas. Taco Mayo is owned by Taco Mayo Franchise Systems, Inc., with corporate offices located in Oklahoma City. The majority of Taco Mayo locations are now franchised.
Also contributing to saving the franchise's name was the idea to upgrade to a “Fresh Mex” style on the restaurants twenty-fifth anniversary. This upgrade included simplifying the menu and showing the customer the freshness of their food by using an open layout bar that displayed the ingredients in plain sight. Some people believe this portion of the upgrade was to distance itself from Taco Bell or other Tex-Mex fast-food chain restaurants; while moving away from these chains, Taco Mayo was only growing closer to being an off-brand, cheaper Chipotle Mexican Grill. This upgrade to “Fresh Mex,” the change from glorified Taco Bell to off-brand Chipotle, has worked well for Taco Mayo. This small franchise has come a long way in its thirty-nine years of service and will continue to provide “pleasant inside dining and fast, friendly and efficient drive-thru service” throughout the upcoming years.