In 1981, a group of businessmen invited Károlyi to join a gymnastics business venture. He decided to invest in the business and the Károlyis relocated to Houston, Texas. The gym ran into financial problems, however, and Károlyi ended up buying it. Karolyi's status as "Nadia's coach" quickly attracted gymnasts to his club. Only three years after his defection, in 1984, Karolyi was back at the Olympics as the individual coach of all-around champion Mary Lou Retton and uneven bars gold medalist Julianne McNamara. Karolyi's clout in America grew after 1984, and by the time the 1988 Olympics rolled around, he was influential enough to be made head coach of the women's team. Karolyi was also the personal coach of three athletes on the squad: balance beam bronze medalist Phoebe Mills, the only female US gymnast to medal in Seoul; Chelle Stack and Brandy Johnson. After the 1988 Olympics, Karolyi's sphere of influence continued to grow, as did the number of elites training in his gym. At one meet in 1989, a journalist dubbed six top Karolyi gymnasts the "six-pack." Although the members of the six-pack would change, the name stuck, as did Karolyi's prominence in the sport. At the 1991 World Championships, an astounding four of the six athletes on the US women's team were trained by Karolyi; the other two were trained by ex-Karolyi club coaches. The situation was almost repeated at the 1992 Olympics, where Karolyi was head coach and five of the seven athletes (six competitors and one alternate) were either trained by him or one of his proteges. Károlyi mostly acted as a personal coach for his athletes Dominique Moceanu and Kerri Strug at the 1996 Olympics, but still managed to draw the spotlight. The image of him carrying an injured Kerri Strug in his arms on her way to the podium to accept her team gold medal became arguably one of the most enduring memories in sports history. (See the photo at OlympicsGallery/jul24_sprain.html). Károlyi retired after the 1996 Olympics. He and Marta still have a ranch and gymnastics camp in Houston. Among the gymnasts Béla and Martha Károlyi have trained are Mary Lou Retton, Betty Okino, Kerri Strug, Teodora Ungureanu, Nadia Comaneci, Kimn Zmeskal and Dominique Moceanu. In total, Károlyi has trained nine Olympic champions, fifteen world champions, sixteen European medalists and six U.S. national champions.

Following the success of the "Magnificent Seven" at the 1996 Olympics, USA Gymnastics experienced a lull. A new age limit kept some of their top gymnasts out of the World Championships in 1997. While American gymnasts did medal in international competitions such as the Goodwill Games and the Pacific Alliance, they were largely unsuccessful in most major meets. In both 1997 and 1999, the American team left the World Championships without a single medal. Following the US team's dismal sixth place finish at the 1999 Worlds, USA Gymnastics attempted to revamp their program by hiring Karolyi to serve as National Team Coordinator. Karolyi required that all national team members attend frequent grueling camps at his ranch near Houston and selection procedures for international meets became more arbitrary. Coaches resented what they felt was Karolyi's intrusion onto their domain; athletes were under a considerable amount of stress. At the 2000 Olympics, where the US team once again came away without a single medal, the tension had escalated to the point where gymnasts were openly speaking out against Karolyi to the media. In 2001, the National Team Coordinator position was handed over to Karolyi's wife, Marta. While Marta has retained some aspects of Bela's program, such as the training camp system (although camps are less frequent now), her approach appears to be different, and more acceptable to both coaches and gymnasts. It has also yielded more impressive competitive results: between 2001 and 2005, American women won a combined total of twenty-four medals in World Championship and Olympic competition.