In his first season in the National Basketball Association (NBA) in 2004–05, Okafor played for the Charlotte Bobcats and was named Rookie of the Year.

[3] Okafor played at Bellaire High School with future Oklahoma State star John Lucas III.

Bellaire was 26–5 in that season, losing 56–42 in the third round of the 2001 UIL state playoffs, to Willowridge High School and future Texas standout T. J. Ford.

Okafor flew under the recruiting radar for much of his high school career, but by the end of his senior year was receiving late interest from top programs and chose to accept a scholarship at the University of Connecticut, choosing the Huskies over Arkansas and Vanderbilt.

He was teammates with Charlie Villanueva, Marcus Williams, Ben Gordon, Hilton Armstrong and Josh Boone, who all went on to play in the NBA.

[6] For his collegiate achievements, Okafor was made a member of the 2004 U.S. National Men's Basketball Team that represented the U.S. at the Olympics in Athens.

On February 5, 2007, he was inducted to the Husky Ring Of Honor at Gampel Pavilion on the UConn campus in Storrs during halftime of the men's basketball game against the Syracuse Orange as part of a ceremony that recognized the accomplishments of 13 former players and 3 coaches.

[8] The following day, he accepted an invitation to join the United States team for the 2004 Summer Olympics, which finished with the bronze medal in Athens.

Highlights of the season included recording 19 straight double-doubles from November 21 through January 1, and finishing seventh among Eastern Conference forwards in NBA All-Star Game fan balloting with 408,082 votes, by far the highest number garnered by any rookie in 2005.

At the end of the season, Okafor beat out his friend and former college teammate and roommate, Chicago Bulls guard Ben Gordon, to win the NBA Rookie of the Year Award.

Okafor finished his rookie season with 44.7% field goal percentage and per-game averages of 15.1 points, 10.9 rebounds (ranked 4th in the league[11]), and 1.7 blocks.

On December 29, 2006, in a home game against the Los Angeles Lakers, Emeka would record 22 points, 25 rebounds, and 4 blocks in over 51 minutes of play, in an epic 133–124 triple overtime victory.

Prior to the start of the 2007–08 season, Okafor turned down a contract extension with the Charlotte Bobcats worth an estimated US$60 million over five years.

Through tough negotiations the Bobcats and Okafor eventually reached an agreement on a six-year, $72 million deal, the largest in franchise history.

“It makes older people feel great, but he’s got to work on his game.... There’s no better guy than him, I just want him to have a passion to play the sport because it ends so quickly.”[16] On July 28, 2009, Okafor was traded to the New Orleans Hornets in exchange for Tyson Chandler.

[17] Charlotte head coach Larry Brown was reportedly willing jettison the franchise's first ever draft pick for another 26-year-old center who is three inches taller because it brought financial relief and because, at 6-foot-10, he felt Okafor had trouble guarding the NBA's top big men.

[15] Head coach Byron Scott was fired after a disappointing 3–6 start and replaced by GM Jeff Bower.

[22] On June 20, 2012, Okafor was traded, along with Trevor Ariza, to the Washington Wizards in exchange for Rashard Lewis and the 46th pick of the 2012 NBA draft.

[24] On October 25, 2013, days before the start of the 2013–14 season, Okafor was traded, along with a 2014 protected first-round draft pick, to the Phoenix Suns in exchange for Marcin Gortat, Shannon Brown, Kendall Marshall and Malcolm Lee.

[34] Filling in for the injured DeMarcus Cousins, Okafor averaged 4.4 points, 4.6 rebounds and 1 block in 26 regular-season games, including 19 starts.

[39] Okafor made his debut for them on December 4, 2019, coming off from bench with a double-double of 11 points, 12 rebounds, two assists and two blocks in a 60–65 loss to the Anyang KGC.