The school, which was constructed at a cost of $15,522,300, contained 55.88 acres of pecan trees, a 750-seat auditorium, and 100 faculty and staff members.

In the 1999–2000 school year, James May became the new principal, replacing Wayne Emerson, and remained in the role until his retirement in June 2008.

During that time KHS achieved recognition as a Recognized High School from the Texas Education Agency as well as a 96th percentile National ranking from Newsweek magazine.

In the 2005–2006 school year, Kempner had a population of 2,616 students: 723 freshmen, 683 sophomores, 597 juniors, and 613 seniors.

In 2013, Navjinder Singh, a worker at the Indian grocery shop Keemat Grocers who was quoted in The New York Times, stated that Kempner has hallways known for particular ethnic groups; for instance, "Desi hallway" refers to an area where students of Indian origins congregate.