Boutayeb was born in Khemisset, Morocco. Although he had been considered more a 5000 m runner before 1988, he was quite unknown until the Seoul Olympics.
The 10,000 m final at Seoul was started at a very fast pace, pushed along mostly by Kenyans, Kipkemboi Kimeli, and Moses Tanui. A small lead group reached the halfway mark at world record pace, at which point Boutayeb moved to lead. He continued the race at world record pace, but deliberately slowed after the bell to finish in a world's fourth fastest time of 27:21.46.
After the Olympic Games, Boutayeb decided to concentrate again on shorter distances, running his personal bests in distances from 1500 m to 5000 m over the couple of next seasons. He placed second in the season rankings for the 1988 IAAF Grand Prix Final. He won a bronze medal in 5000 m at the 1991 World Championships held in Tokyo. At the Barcelona Olympic Games, Boutayeb came fourth in 5000 m, only 0.75 seconds behind the winner Dieter Baumann from Germany.
After being eliminated in his heat of the 5000 m at the 1993 World Championships in Stuttgart, Brahim Boutayeb gave up the competitive athletics and preferred to concentrate on his new sporting interest as a rally driver.