[2] Mbenga was born and raised in Kinshasa, Zaire, now known as the Democratic Republic of the Congo, where his father was a government employee.

[1] While his father was eventually unable to save himself, he did manage to negotiate on behalf of his wife and son, as Mbenga and his mother escaped the nation and were given asylum in Belgium.

On July 14, 2004, Mbenga signed a two-year, $3.4 million contract with the Dallas Mavericks and joined them for the 2004 NBA Summer League.

In July 2005, Mbenga re-joined the Dallas Mavericks for the 2005 NBA Summer League, and went on to play in 43 regular season games for the franchise in 2005–06.

During the 2006 Western Conference Finals against the Phoenix Suns, Mbenga was suspended for six games for going into the stands, after he saw the wife of coach Avery Johnson being harassed by fans.

After again playing for the Mavericks in the 2006 NBA Summer League, Mbenga re-signed with the franchise to a three-year, non-guaranteed contract on July 13, 2006.

[7] He returned to the court on October 23, 2007, in the Mavericks' preseason finale against the Chicago Bulls where he recorded 5 rebounds, 2 blocks and 1 assist in 12 minutes of action.

[13] On March 6, 2009, Mbenga recorded a then career high 10 points on 4–5 shooting, along with 4 rebounds and 5 blocks, in a 110–90 win over the Minnesota Timberwolves.

[15] Two days later, Mbenga recorded his first career double-double with 10 points and 12 rebounds, in addition to 4 blocks, in a 104–88 win over the New Orleans Hornets.