McAlister had a solid rookie season in which he recorded 47 tackles (45 solo), 5 interceptions, and 16 passes deflected. He made his NFL debut at the St. Louis Rams on September 12, 1999. At season's end, he was named to College & Pro Football Newsweekly's 1999 All-Rookie Team. McAlister had another solid season in 2000 as the Ravens won the Super Bowl and he had a key interception in Super Bowl XXXV against the New York Giants. During the regular season, he also intercepted New York Jets and former Baltimore Ravens QB Vinny Testaverde and returned it 98 yards for a touchdown.
McAlister earned his first Pro Bowl selection in 2003. He had 43 tackles. McAlister also intercepted three passes for 93 yards. That included an 83-yard run for a score.
In 2004, McAlister signed a 7-year, 55 million dollar contract.
McAlister had arguably the best season of his career in 2006. He had two touchdowns that year and made his third Pro Bowl. But his last two seasons in Baltimore were marked by injuries and inconsistent play. In 2008, in 5 starts before being put on Injured Reserve, he did however amass 16 tackles, 3 INTs and 1 fumble recovery, showing some of his old form.
On November 17, 2009, McAlister signed with the New Orleans Saints. In a December 6 game at the Washington Redskins, McAlister forced a fumble in overtime, which started the drive resulting in a game-winning field goal for New Orleans. However, he was released on December 8, just two months before the Saints would go on to win Super Bowl XLIV. McAlister finished 2009 with 4 tackles and the forced fumble. He has not played in the NFL since.
Chris McAlister's father James McAlister also played in the NFL, in three seasons for the New England Patriots and Philadelphia Eagles during the 1970s. In 1996, McAlister was convicted and served a brief sentence for a petty theft charge. McAlister is divorced and has two daughters. McAlister was married for 13 months. By 2011, according to court documents he filed in hopes of getting his child support payments lowered, McAlister was forced to move back in with his parents. He also disclosed that he has not had any income since 2009.