In his first professional season for Budućnost, Pavlović played in 14 games in the YUBA League and averaged 1.4 points per game. In his second season, Pavlović played in three games in the YUBA League and averaged 6.7 points. Also, Pavlović played two games in the Euroleague.
In his last season in Podgorica, Pavlović played in 20 games in the YUBA League and averaged 10.1 points and 2.4 rebounds per game. Pavlović averaged 9.6 points on 54% shooting for Budućnost in the Euroleague, including a season high 21 points against Tau Ceramica.
Pavlović was selected by the Utah Jazz with the 19th pick in the 2003 NBA draft. His American agent Marc Cornstein issued a clarification in response to a misleading Eurobasket.com biography mixing Aleksandar Pavlović with an Aleksander Pavlović who played college basketball at La Salle University and Shippensburg University of Pennsylvania.
In 79 games played (14 starts), Pavlović averaged 4.8 points and 2.0 rebounds. He scored a season high 18 points on December 3, 2003 against the Houston Rockets and grabbed nine rebounds on two occasions.
Pavlović was selected by the Charlotte Bobcats in the expansion draft on June 22, 2004, and was traded to the Cleveland Cavaliers for a 2007 first round draft pick the next day. In 65 games played (nine starts), Pavlović averaged 4.8 points and 1.1 rebounds. He scored a season high 17 points on two occasions and scored in double digits on nine occasions.
In 53 games of the 2005–06 season, he started 19 times and averaged 4.5 points and 1.5 rebounds. He scored a season high 21 points on February 21, 2006 against the Orlando Magic. Pavlović played three minutes over three playoff games and recorded only one rebound.
In 67 games played (28 starts) in 2006–07, Pavlović averaged a career high 9.0 points, along with 2.4 rebounds and 1.6 assists. He scored 20 points or more on seven occasions, including a new career-high 25 points on March 13, 2007 against the Sacramento Kings. Approximately two weeks later, Pavlović had a career high six three point field goals made (of 7 attempts) against the New York Knicks. After occasional starts in the beginning of 2007, Pavlović was installed as the Cavaliers' starting shooting guard on March 1, 2007 and started the remaining 24 regular season games. As a starter, Pavlović averaged 12.7 points, 3.0 rebounds and 2.3 assists.
Pavlović started all 20 of Cavaliers' 2007 playoff games. He had playoff highs of 17 points in a game 2 victory over the New Jersey Nets in the Eastern Conference Semifinals and nine rebounds in a Game 5 overtime victory over the Detroit Pistons in the Eastern Conference Finals.
In the 2007 offseason Pavlović was a restricted free agent. On October 30, 2007 after nearly a month holdout he signed a three-year, $13.7 million extension with the Cavaliers. Pavlović injured his left foot on January 23, 2008 in a game against the Washington Wizards. He returned against the New Jersey Nets on March 12. He started but was held scoreless in 9 minutes of action. On March 14, Pavlović had a season-high 24 points on against the Washington Wizards. He and scored double digit points in 15 total games.
During the 2007–08 season, Pavlović played in 51 games (45 starts) and averaged 7.4 points, a career high 2.5 rebounds and a career high 1.6 assists. In eight playoff games, Pavlović averaged 3.5 points and 1.3 rebounds.
In the following 2008–09 season, the Cavaliers were beaten by the Orlando Magic, in the 2009 Eastern Conference Finals, 4 games to 2. Pavlović became trade bait as talks with the Phoenix Suns were rekindled from earlier in the season and on June 25, 2009, Pavlović, Ben Wallace, and the 46th overall pick were traded to Phoenix for Shaquille O'Neal. On September 14, 2009, he was bought out by the Suns.
On September 17, 2009, Pavlović signed a one-year, $1.5 million contract with the Minnesota Timberwolves. In 71 games, he averaged 3.7 points per game.
On January 10, 2011, Pavlović signed a 10-day contract with the Dallas Mavericks. Pavlović started his first game for the Mavericks on the last day of his contract, scoring 11 points in the Mavericks' 109-100 win over the Lakers. On January 20, 2011, he signed a second 10-day contract with the Mavericks. On January 30, 2011, his second 10-day contract expired and the Mavericks did not sign him for the rest of the season.
On February 4, 2011, Pavlović signed a 10-day contract with the New Orleans Hornets. On February 14, 2011, his 10-day contract expired and the Hornets did not sign him to a second 10-day contract.
On March 3, 2011, Pavlović signed with the Boston Celtics for the rest of the 2010–11 season. In his first appearance with Boston on March 6, 2011 in a game against the Milwaukee Bucks, he played 12 minutes going 1-2 for three and 1-3 overall, recording 3 points and 2 steals.
His contract expired following the 2011 playoffs and he returned to Montenegro to work out for the summer. On December 12, 2011, upon the end of the 2011 NBA lockout, Pavlović re-signed with the Celtics. The 2011–12 NBA season opened on Christmas Day 2011 and Pavlović started for an injured Paul Pierce. He played 15 minutes without attempting a shot or scoring a point. In the second to last game of the season, a 78-66 win over the Heat, Pavlović scored 16 points off the bench. In 45 games (7 as starter), he averaged 2.7 points in 11.7 minutes per game.
On July 20, 2012, Pavlović was traded to the Portland Trail Blazers in a three team deal.
On July 6, 2013, Pavlović was waived by the Trail Blazers.
On February 10, 2014, Pavlović returned to Europe and officially signed with Serbian powerhouse Partizan Belgrade for the rest of the 2013–14 season. Partizan finished season by winning its 13th consecutive domestic title, defeating arch rivals Red Star Belgrade by 3-1 in the final series. In the final series he averaged 11.7 points and 2.7 rebounds per game. Even though Pavlović was the most experienced player in the roster, it was his first championship win in his professional career. The day after the game, he said that winning a championship with Partizan was his greatest career accomplishment.
On December 1, 2014, Pavlović returned to Partizan and signed a contract for the rest of the season. In the ABA League debut in the new season, he led his team in a 89–80 victory over Mega Leks by scoring 26 points and having 4 rebounds and assists. Over 19 Adriatic League games, he averaged 11.9 points and 3.7 rebounds per game.
On July 9, 2015, Pavlović signed a one-year contract with the Greek club Panathinaikos. On April 21, 2016, he was released by the club.
Pavlović was a member of the Serbia and Montenegro Under-20 national team and played at the 2002 European Under-20 Championships in Lithuania. He was a member of the Serbia and Montenegro national team at the 2004 Olympic Games, playing in four games, averaging 3.5 points and 1.8 rebounds. Two years later, Montenegro, his native country, declared independence from the State Union of Serbia and Montenegro. After that, Pavlović said that he would like to play for the Serbian national team. However, he did not play for the Serbian or the Montenegrin national team. When asked about a possible comeback in February 2014, he responded with: "I'm not thinking about the national team. To me, it became a political matter, not a sports matter. This is why I decided not to commit [to the national team]."
Note: The EuroLeague is not the only competition in which the player participated for the team during the season. He also played in domestic competition, and regional competition if applicable.