Harold Butler bought Naugles in 1971 when the chain consisted of three restaurants. The chain was expanded by a system of non-exclusive franchises, which was ruled unlawful by a federal court. He built it up to 225 restaurants by 1986, when he sold the chain to Collins Food International. Naugles merged with Del Taco in 1988. A few of the Naugles menu items, such as those with the "Macho" designation, found their way into the regular Del Taco menu. Also, the Naugles bun taco can still be ordered from Del Taco even though it does not appear listed on the menu.
A few independent franchises kept the Naugles name until 1995.
In the Naugles TV commercials, the character of Señor Naugles was played by character actor Roger C. Carmel and comedian Avery Schreiber. Hispanic actors had refused to take part in the advertisements due the stereotyped image presented of Mexicans.