Mendy turned professional in 1983 and compiled a record of 45–4–2 (1 NC) before facing Miguel Ángel González for the WBC lightweight title, he would lose via fifth round stoppage.
WBC lightweight title Mendy would get another shot at the same title two years later but this time would be successful and won the belt vacated by González by beating Lamar Murphy. He lost the title in his first defense to
Stevie Johnston the following year.
WBA lightweight title In 1998, he captured the
WBA lightweight title with a decision win over
Orzubek Nazarov. He defended the belt once before losing it to Julien Lorcy in 1999. He retired the following year. ==Professional boxing record==