He played for three years under legendary coach Henry Iba at Oklahoma A&M. He was the head coach at Texas Western College (renamed the University of Texas at El Paso in 1967) from 1961 to 1999, including the 1966 season when that school's basketball team won the NCAA Men's Division I Basketball Championship over the Wildcats of the University of Kentucky, coached by hoops legend Adolph Rupp.

This event had societal implications well above its sporting ones. Texas Western had been recruiting and playing African American players in the 1950s, when no schools in the Southeastern Conference or the former Southwest Conference would offer them athletic scholarships. When Haskins arrived in El Paso, he had inherited three black players from his coaching predecessor. One of them, Nolan Richardson, would go on to win a national title as the head coach at Arkansas.

Haskins recruited and played black players to an even greater extent. After Texas Western dropped Utah and Kentucky defeated Duke in the national semifinals, the championship game was played on national television, and to the consternation of most pundits, Haskins chose to play an all-black starting lineup; the team defeated Kentucky's all-white one. In contrast to Haskins, Kentucky coach Adolph Rupp was largely regarded as a supporter of racial segregation, or at least very reluctant to recruit black players, although this assessment is not completely supported by all evidence, and remains controversial to this day.

The game was not as large an upset as was often depicted after the fact; both teams were 27-1 entering the final game, and Texas Western was ranked #3 in that season's final polls. However, it is safe to say that the Texas Western team was not highly regarded at the start and through most of that season, and were seen as the "Cinderella Team". It is widely held, but untrue, that Haskins was the first to play black players; as noted above, Texas Western had black players before Haskins' arrival, and many schools outside the South had long since integrated their athletic programs. It is true that the 1966 Miners were the first team in NCAA basketball to have an all-black starting lineup. It is also true that Texas Western, before Haskins' arrival, was the first college in a Southern state to integrate its athletic teams.

Also contrary to later legend surrounding the championship team, Texas Western was not struggling in basketball prior to 1966. The Miners reached the NCAA Tournament in 1963 and 1964 and played in the National Invitation Tournament in 1965. On numerous occasions, Haskins has stated that he believed his 1964 team could have won the NCAA Tournament had All-American Jim "Bad News" Barnes not fouled out after playing only 8 minutes in a 64-60 loss to Kansas State in the Tournament.

This game did much to change the perception of African-American athletes and to speed the desegregation of intercollegiate sports. Haskins coached at UTEP for many years after his historic championship season, with much success, but never came close to repeating the team's 1966 performance. One highlight of his career and considered one of his most strategic games was his outcoaching of the University of Kansas' Roy Williams in the 1992 NCAA Tournament. Kansas, the #1 ranked team in the nation, was heavily favored, but Haskins was able to slow down the game and spread the floor, allowing his quick point guard, Eddie Rivera, to penetrate the Jayhawk defense, only to pass to wide open Miners. Don Haskins was also an assistant coach for Hank Iba in the 1972 Summer Olympics in Munich.

Although Haskins was never able to duplicate his 1966 success, he is nonetheless regarded as an important figure in basketball history due to his courage in facing the sport's racial issues directly. He was elected to the Basketball Hall of Fame in 1997. The players he coached at UTEP over the years included future NBA all-stars Tiny Archibald, Tim Hardaway, and Antonio Davis. Other UTEP alums moving to the NBA included Marlon Maxey and Greg Foster. He was also a mentor for several future coaches, including Nolan Richardson and Tim Floyd. Haskins' hunting partner, and one of his best friends, is Texas Tech coach Bobby Knight. Don Haskins' record is 719-353.