Ten years after the establishment of a graduate chapter in Monroe, which is located in the northern part of the state, an undergraduate chapter was chartered in the southwestern part of the state. At the University of Southwestern University (now formally known as the University of Louisiana at Lafayette) located in Lafayette, Louisiana, the Zeta Xi Chapter was chartered on May 5, 1968. An error was made when the charter was typed, designating the chapter as "Theta Xi." The correction was made on January 10, 1969 to change the name to Zeta Xi. Zeta Xi recognizes its charter date as May 5, 1968.

The charter members were:

Brothers Matthew Augustine, Ronnell Badon, Samuel Guillory, Edgar Jordan, Joseph Malbroue, Wilfred Pierre, and Steven Randle.