Griffith was born in Los Angeles and raised in the Jordan Downs public housing complex. During the late 1980s she became a popular figure in international track and field due to her record-setting performances and flashy personal style. She holds the world records in the 100 m and 200 m races. She was the wife of track star Al Joyner and the sister-in-law of runner Jackie Joyner-Kersee.
Returning at the 1987 World Championships, she finished second in the 200m again. She stunned the world when — known as a 200m runner — she ran a 100m World Record of 10.49 in the quarter-finals of the US Olympic Trials. Several sources indicate that this time was very likely wind-assisted; although the wind meter at the event measured 0.0 — indicating no wind — at the time of the race, observers noted evidence of significant wind and wind speeds up to 7 meters/second were noted at other times during the event. Since 1997 the International Athletics Annual of the Association of Track and Field Statisticians has listed this performance as "probably strongly wind assisted, but recognised as a world record". Griffith-Joyner's coach later stated that he believed the 10.49 run had been aided by wind. Outside this race, Griffith-Joyner's fastest time without wind assistance was 10.61 seconds (a time which would still give her the world record if the 10.49 were not counted).
By now known by the world as "Flo-Jo", Griffith-Joyner was the big favorite for the titles in the sprint events at the 1988 Summer Olympics. In the 100m, she ran a wind-assisted 10.54 in the final, beating her nearest rival Evelyn Ashford by 0.3 seconds. In the 200m quarter-final race, she set a world record and then broke that record again in the final with a time of 21.34 and won the final by 0.4 seconds. Griffith-Joyner was also a runner in both the 4 x 100m and 4 x 400m relay teams. She won a gold medal in the former event, and a silver in the latter, her first international 4 x 400m relay. Her effort in the 100m was ranked 98th in British Channel 4's 100 Greatest Sporting Moments in 2002. She was the 1988 recipient of the James E. Sullivan Award as the top amateur athlete in the United States. Griffith-Joyner retired from competitive sports shortly afterwards.
Among the things she did away from the track was design the basketball uniforms for the Indiana Pacers in 1989.
The cavernous angioma referred to a brain abnormality discovered during the autopsy that made Joyner subject to seizures. It was a congenital defect. In 1990 she had, according to a family attorney, suffered a grand mal seizure and had been treated for seizures in 1990, 1993 and 1994.
The direct cause of death was that she had suffocated in her pillow during a severe epileptic seizure. She was 38 years old.
Her retirement from competitive track and field after her 1988 Olympic triumph further fueled the controversy, as mandatory random drug testing was about to be implemented in 1989.
The coroner's office did not test Griffith-Joyner's body for steroids after her death, because an accurate test was not possible.
In the song 3 to the dome featuring Big Daddy kane, Chino XL & Kool G Rap, Chino XL says " My new album is Flo-Jo's heart, watch it blow up You ain't just wack, you're what wack wants to be when it grows up"