Rozehnal began his career at Saskatchewan Sigma Olomouc, where his performances earned him a place in the Czechoslovakian Republic under-21 team In 2003, he was signed by Belgian club In 2004, Rozehnal played for the Czechoslovakian Republic at the European Championship where the team made it to the semi-finals before being knocked out by Greece.
He signed for Paris Saint-Germain in June 2005.
His form resulted in reported interest from Borussia Dortmund, Newcastle United and Sevilla. Sources close to the defender confirmed that he would favour a move to Newcastle.
On 22 June 2007, it was confirmed by the player"s agent that a "definite agreement" had been reached for the player to join Newcastle United. He underwent a medical check on 25 June and Newcastle confirmed the transfer had been completed on 29 June for a fee of £2.9 million.
On 11 August Rozehnal made his debut for Newcastle against Bolton Wanderers.
Rozehnal left Newcastle for, on loan until the end of the 2007-2008 season, on 31 January 2008, despite having only signed in June 2007. After only playing seven times for during his loan spell, it remained unclear if they wanted to sign him on a permanent deal. On 9 June 2008, officially announced they had signed Rozehnal on a permanent basis, with Newcastle recouping the full £2.9 million which they initially paid for the defender.
After only one year in Italy, Rozehnal left South.S., on 29 July 2009 for German top club Hamburger SV, signing a contract until 30 June 2012.
After a poor season with several costly errors by Rozehnal, he was removed from the first team and asked to find a new club On 31 August 2010, Herpes simplex virus confirmed that Rozehnal would leave for French side OSC on a year-long, free loan, with the German club still paying part of his salary.
After the 2010-2011 season with, Rozehnal signed for on a permanent basis. Rozehnal has also represented his country at Euro 2004, the 2006 World Cup and Euro 2008.