Vašíček returned to the Greyhounds for the 1999–2000 season, where he improved his offensive numbers to 26 goals and 72 points in 54 games to finished second in team scoring.

After a solid training camp in September 2000, Vašíček made the Hurricanes' NHL roster and ultimately spent the entire 2000–01 season with the team.

He then scored his first career NHL goal on October 13 after he beat goaltender Trevor Kidd of the Florida Panthers in an eventual 2–2 tie.

He then played in his first-ever Stanley Cup playoff game on April 12, 2001, scoring a goal against Martin Brodeur of the New Jersey Devils in a 5–1 loss.

Vašíček began his 2006–07 season on his Predators debut on October 5, 2006, marking the occasion by scoring a goal against Nikolai Khabibulin of the Chicago Blackhawks in an 8–6 loss.

Vašíček, however, struggled with the Predators — in 38 games, he had just four goals and 13 points, prompting Nashville, on February 9, 2007, to trade him back to Carolina in exchange for Éric Bélanger.

He made his Islanders debut on October 5 and marked the occasion by scoring a goal against Ryan Miller of the Buffalo Sabres in a 6–4 win.

In 18 playoff games, he had a KHL-high 22 points, scoring seven goals and adding 15 assists, though Yaroslavl eventually lost in the Western Conference Finals.

He played in the 2000 World Junior Ice Hockey Championships held in Sweden, scoring a goal and four points in seven games as the Czechs won the gold medal.

Vasicek then appeared at the senior level in the 2003 IIHF World Championship in Finland, scoring two assists in nine games as the Czechs finished fourth.

His next international appearance was at the 2009 IIHF World Championship held in Switzerland, where he scored one goal and two assists in six games as the Czech Republic finished sixth.

[2] On September 7, 2011, Vašíček was killed when a Yakovlev Yak-42 passenger aircraft, carrying the entire Lokomotiv team, crashed just outside Yaroslavl, Russia.