After playing junior hockey in his native Czechoslovakia, Petr Sykora moved to North America in 1993-94 to play in the IHL. He played for his home country at the World Junior Championships in 1994 and 1995 and was selected by the Devils in the first round of the 1995 NHL Entry Draft.
Sykora made his NHL debut with the Devils in 1995-96 and split the next three seasons with New Jersey and their AHL affiliate in Albany before playing his first full year in the NHL in 1995-96 where he was named to the NHL All-Rookie Team after finishing the year with 42 points. Sykora and the Devils captured Lord Stanley's Cup in the spring of 2000 and headed back to the finals the next year, only to be beaten by the Colorado Avalanche in seven games. Although the Devils fell short in their hopes of repeating as Cup champions, Sykora managed to esablish a career high in goals (35), assists (46) and points (81).
An offensively gifted player, Sykora represented his homeland at the 2002 Winter Olympics in Salt Lake City before being dealt to the Anaheim Mighty Ducks in the summer of 2002.
In an unexpected twist of fate, Sykora faced off against his former Devil teammates in the 2003 Stanley Cup Final. Despite leading his team with a team-high 13 points, Sykora watched the Devils win the series in a hard-fought seven games. The former first rounder went on to play one more full season with the Ducks before being dealt to the New York Rangers midway through the 2005-06 season.
In 40 games with the Rangers, Sykora totaled 31 points (16-15-31) however was not resigned by the club in the off-season. The Edmonton Oilers signed the free agent on August 11, 2006. In Edmonton, Sykora appeared in all of the teams 82 regular season games, finishing tied for first in scoring on the club with 53 points. For the seventh time in his career, Sykora eclipsed the 20 goal mark while helping shore up the Oiler power play.
Following the regular season, Sykora signed as a free agent with the Pittsburg Penguins in the off-season. In signing with the Penguins, Sykora was re-united with former Magnitogorsk teammates Evgeni Malkin and Sergei Gonchar. This move that would prove fortuitous for both Sykora and the Penguins as the team would go on to win the Stanley Cup that June. Though injuries limited Petr to just 7 playoff games, his leadership was instrumental.
Aside from his World Junior and Olympic appearances, Sykora represented his homeland at the 1996 and 2004 World Cup and the 1998, 1999 and 2005 World Championships.