Chára was born in Trenčín, Slovakia. His father, Zdenek, was a 6 ft 2 inch Olympic wrestler. He was drafted 56th overall by the New York Islanders in the 1996 NHL Entry Draft. During the 2001 draft, he was traded to the Senators as part of a package-deal with Bill Muckalt and the second overall pick (used to draft Jason Spezza) in exchange for Alexei Yashin.

 

In 2003, Chára made his first appearance at the NHL All-Star game, and in the skills competition recorded the second hardest shot after Al MacInnis.

 

Chára ended with the third highest +/− in the 2003–04 season, only behind the Tampa Bay Lightning's Martin St. Louis and the Vancouver Canucks' Marek Malik, who were tied for first. At the conclusion of the season, Chára was the runner-up to Scott Niedermayer for the James Norris Memorial Trophy, which is awarded to the best defenceman of the season, and he was voted on the first NHL All-Star team.

 

Chára had a career year in 2005–06, posting personal bests in goals (16), points (43), and shots on goal (212). He was named to the NHL Second All-Star team.

 

On July 1, 2006, he signed a five-year, $37.5 million contract with the Boston Bruins. On October 3, 2006, he was named captain of the Boston Bruins, a role left vacant since Joe Thornton's departure. On January 13, 2007, Zdeno was named to the Eastern Conference roster in the 55th National Hockey League All-Star Game In Dallas, Texas. He won the NHL's hardest shot competition at the 2007 Skills Competition, clocking a shot at 100.4 mph (161.6 km/h)

Chára has represented Slovakia in five World Championships as well as in one World Cup.