The 30-year-old Marquis was 11-9 with a 4.53 ERA last season for the NL Central champion Cubs. The Rockies also receive cash as part of the deal.
Colorado has a solid core of starters in Aaron Cook, Jeff Francis and Ubaldo Jimenez. Marquis will likely compete for a spot at the back of the rotation with Jorge De La Rosa, Jason Hirsh, Franklin Morales, Greg Smith and Greg Reynolds.
Marquis has had double-digit wins in each of the last five seasons, surpassing 190 innings four times. He's also a capable hitter for a pitcher, with five home runs and 40 RBIs in his nine-year career.
"The addition of Jason to our ballclub brings us the veteran leadership and depth to our rotation that we have been seeking to add this offseason," Colorado general manager Dan O'Dowd said in a statement.
Chicago was looking to trim salary after reaching a preliminary agreement with free-agent outfielder Milton Bradley on a $30 million, three-year contract Monday.
It is thought the Cubs will pick up about $1 million of Marquis' $9,875,000 salary in 2009. Vizcaino will earn $3.5 million next season and his contract contains a $4 million club option for 2010 with a $500,000 buyout.
Chicago general manager Jim Hendry wouldn't call the trade a salary dump, just a way to keep the payroll in line.
"We're no different than anybody else, except maybe my buddy Brian Cashman," Hendry said, playfully taking a jab at the New York Yankees GM who has spent $423.5 million to lure three top free agents this offseason. "We have a fair payroll. We have one of the better payrolls in this game, and we still do."
Vizcaino struggled in his first year with Colorado, going 1-2 with a 5.28 ERA in 43 relief appearances.
"I haven't seen much of him in person in the last year, but our scouts still felt like he had enough juice, enough savvy to pitch in the seventh, eighth inning," Hendry said.
It's the second trade the Rockies have made this offseason. They dealt All-Star outfielder Matt Holliday to Oakland in November for reliever Huston Street, promising outfielder Carlos Gonzalez and Smith.
The Rockies never found their footing in 2008, falling back to 74-88 a year after winning the NL pennant.
Colorado fired several members of its coaching staff, leading to former manager Don Baylor's return as hitting coach. The team also brought in former major league manager Jim Tracy as bench coach and Rich Dauer as third base coach.
Relief pitcher Alan Embree agreed to a one-year deal with Colorado in December.
"We're just trying to make the club better, which I think we are," Hendry said.