Born from the ashes of WWII, the CETME design group was established in Spain, and staffed by many Mauser employees like Dr. Ludwig Vorgrimler, who brought their research and designs with them. They would later develop and adopt the CETME C, better known to American shooters and collectors under its German licensed designation: the G3 / HK91 in 7.62x51 / .308.

Faced with the transition by militaries to the 5.56 in the 1970s, and with their pending entrance into NATO, Spain and CETME began in earnest to develop a 5.56 rifle for their military. The result was the last roller-locking rifle to be adopted by any military, and the first and only one specifically designed for the 5.56/.223 from the ground up, the CETME L.