Cherifi, known as "Billy", began his pro career in 1989 and challenged for the WBC Super Middleweight Title in 1997 against Robin Reid, losing a split decision. After the loss, he dropped down in weight and took on WBC Middleweight Title holder Keith Holmes, winning a decision although he was dropped in the 9th. In 1999, he lost the belt in his first defense to Holmes, via 7th round KO. In 2000 he got a shot at WBA Middleweight Title holder William Joppy. Cherifi was dominated and was down in Rounds 8 and 9, and lost a decision. In 2001 he took on Harry Simon for the interim WBO Middleweight Title and lost a decision in what would be his last shot at a major title. He retired in 2005 after being TKO'd by Rudy Markussen.