Voráček was taken first overall in the 2006 Canadian Hockey League (CHL) Import Draft and played two seasons with the Halifax Mooseheads of the Quebec Major Junior Hockey League (QMJHL). He also represented the Czech Republic at the World Junior Ice Hockey Championship in 2007 and 2008. On 2 August 2007, he signed a three-year, entry-level contract with the Columbus Blue Jackets, the NHL organization that drafted him seventh overall in the 2007 NHL Entry Draft.