Tkachuk has earned the nickname "Walt" (given to him by Eddie Olczyk), possibly in reference to Walter Tkaczuk, a star center who played for the New York Rangers from 1967 to 1981.

The two players' last names are pronounced similarly but spelled differently (being the Polish and English transliterations, respectively, of the Ukrainian "Ткачук"), and the two men are not related to each other.

With his strong play in front of the net, using his size and strength to battle opposing defensemen, St. Louis Blues broadcasters and fans dubbed Tkachuk "Big Walt.

"[9] Only days after the end of the 1992 Winter Olympics, Tkachuk made his NHL debut on February 28, 1992, against the Vancouver Canucks, where he tallied an assist.

While the then-new collective bargaining agreement allowed restricted free agents to negotiate directly with other teams, Tkachuk was initially reluctant to sign an offer sheet since Winnipeg would have the right to match it.

[10] However, to the disappointment of both the Blackhawks and Tkachuk, any assumption that the organization's poor financial situation would preclude them from meeting such obligations quickly proved incorrect as the Jets matched the offer-sheet within six hours.

Due to the contract dispute, Tkachuk was stripped of the captaincy and replaced by Kris King; nonetheless, he set a career-high 50 goals and 98 points, the closest he ever came to reaching the 100-point plateau.

[11] Going up against the Presidents' Trophy-winning Detroit Red Wings, the Jets lost in six games, with Tkachuk scoring a goal and two assists in the series.

[13][14] After struggling with injuries for the next two seasons, the Coyotes traded Tkachuk to the St. Louis Blues in 2001 in exchange for Ladislav Nagy, Michal Handzuš, Jeff Taffe and a first-round draft pick (Ben Eager), where he was re-united with former teammate Dallas Drake, who had signed a free agent deal with the Blues in the summer of 2000.

The Blues made it to the Western Conference Final in the playoffs that season, ultimately losing to the Colorado Avalanche, the eventual 2001 Stanley Cup champions.

Tkachuk experienced several injuries while playing with the Blues, and was briefly suspended by the team when he reported to training camp overweight, failing his physical at the beginning of the 2005–06 season.

Since the Blues acquired exclusive negotiating rights with Tkachuk and re-signed him to a two-year deal, Atlanta received a conditional fourth-round pick in 2008.

Blues Head Coach Andy Murray announced that he would try a line where Tkachuk would be centering Kariya on left wing and Brad Boyes on the right.

[23] Their two sons, Matthew and Brady, play in the NHL, and their daughter, Taryn, is an NCAA Division I field hockey player with the University of Virginia.