After growing up in his birthplace of Teaneck, New Jersey, West went to high school at Garner Magnet High School in Garner, North Carolina and at Hargrave Military Academy in Chatham, Virginia and won First Team All-State honors in North Carolina. He played college ball for the Xavier Musketeers in Cincinnati, Ohio. In 2003 he became the first Musketeer to ever win the AP Player of the Year.
West attended and graduated from Xavier University in Cincinnati, Ohio. There, he was a four-year starter on the basketball team. West was the first XU player to get his number retired while still playing for the Musketeers, during which he led Xavier to a top 10 national ranking and a #3 seed in the NCAA Tournament. West was named as a first-team All-American his senior year and the 2003 Associated Press and United States Basketball Writers Association National Player of the Year, averaging 20.1 ppg and 11.8 rpg as a senior while leading XU to its second straight 26–6 season. West led Xavier to 94 wins in his four seasons while finishing as Xavier's all-time blocked shot leader (228 blocks) and second on XU's all-time scoring (2,132 points) and rebounding (1,308 rebounds) lists. West was also named as the Atlantic 10 Conference Player of the Year three years in a row. As a senior, he was selected as the Lowe's Senior CLASS Award winner, recognizing him as the nation's top senior men's basketball player.
In October 2007, Sports Illustrated released Sports Illustrated: The Basketball Book, which featured West on its NCAA All-Decade Team for the decade beginning in 2000. He was joined by Connecticut's Emeka Okafor and three Duke players, Jay Williams, J. J. Redick and Shane Battier.
New Orleans Hornets
West was drafted by the New Orleans Hornets in the first round, eighteenth overall in the 2003 NBA Draft. After recording modest production in his first two seasons, in 2005–06 West enjoyed a breakthrough, averaging 17.4 points and 7.4 rebounds with a .512 FG% in 74 games. That year, he finished second in the voting for the NBA Most Improved Player Award, behind Boris Diaw of the Phoenix Suns. He also saw some time at center, due to the team's lack of a true big man. That season he demonstrated an ability to perform under pressure, as he converted three game-winning jump shots.
In 2006–07, West ended the season averaging 18.3 points, 8.2 rebounds and 2.2 assists. Despite missing 30 games due to an elbow injury, West recorded five games of 30 or more points and 13 games of 20 or more points.
West again increased his statistical production in 2007–08, and was selected to his first NBA All-Star Game as a reserve, along with teammate Chris Paul. Paul later stated that he would rather not play with a power forward in the league other than West, because "he's not in it for the spotlight, all he cares about is getting buckets [scoring]." West reinforced his desire to be a team player in a 2008 postseason interview, saying that he does not care about being overlooked but would rather focus on "play[ing] and be[ing] as effective as possible" when he is out on the court.
In 2008–09 West repeated as an all-star and posted a new career high by scoring 21.0 points per game.
On March 25, 2011, during one of the New Orleans Hornets' last games of the season vs. the Utah Jazz, West came down awkwardly after a dunk. The event occurred with 22.3 left in the fourth quarter. West tore his anterior cruciate ligament in his left knee.
On June 27, 2011, West confirmed he was opting out of the final year of his contract to become a free agent.
On December 11, 2011, West agreed to a 2 year deal with the Indiana Pacers, reportedly worth $20 million.
On January 12, 2013, West recorded his 1st career triple-double with 14 points, 12 rebounds, and 10 assists.
West re-signed with the Pacers on July 10, 2013.