He first entered the 125cc World Championship in 2000. He was 17th overall in 2001, then divided his time between 125cc and the 250cc championships in 2002. He remained in the 250cc World Championship until 2006, finishing 12th overall with a best of 7th that year.
For 2007 he was the surprise choice to replace Roberto Rolfo at the formerly race-winning SC Caracchi Ducati team in the Superbike World Championship. On a customer Ducati 999 F05 he frequently troubled the top sixteen in qualifying. He finished the season 14th with a best race result of 8th.
For 2008 he rode a customer Ducati 1098 RS 08 for the Guandalini Racing by Grifo's team. He finished the 2008 season in 13th place in the championship.
For 2009 Smrž continued with the Guandalini Racing Team, gaining his first podium finish (3rd) in the fourth round of the season at Assen and first pole position in the eighth round at Misano Adriatico. This time he finished 10th overall.
Smrž remained with the team in 2010, running under the B&G moniker after a partnership deal with the former Sterilgarda Ducati team.5 After a string of mechanical failures midseason, the team switched to an Aprilia bike, marking the first time Smrž had ridden anything other than a Ducati in the class.6 He was the fastest Aprilia in qualifying at Silverstone.7
Smrž lives in Zlín.
(key) (Races in bold indicate pole position) (Races in italics indicate fastest lap)
"'Kuba' overcomes the works boys in Q2". Superbike World Championship. Infront Motor Sports. 15 May 2010. Retrieved 5 July 2010. http://www.worldsbk.com/en/news/latest-news/3391-kuba-overcomes-the-works-boys-in-q2.html ↩
GMT94 Yamaha wrests pole at Oschersleben FIM EWC.com, 8 June 2018. They placed ahead of BMW-mounted Mercury Racing, who will race without Jakub Smrž, injured in qualifying yesterday. Retrieved 22 July 2018 https://www.fimewc.com/gmt94-yamaha-wrests-pole-at-oschersleben/ ↩
8 h Oschersleben 2018: Preview a harmonogram Archived 23 July 2018 at the Wayback Machine silnicnimotorky.cz This completely Czech team, which is comprised of Jakub Smrž, Matěj Smrž and Karel Hanika.... Retrieved 22 July 2018 (in Czech) https://silnicnimotorky.cz/sport/endurance/8-h-oschersleben-2018-preview-a-harmonogram/ ↩
Hedger steps up for the injured Smrz at Lloyd and Jones Bowker Motorrad BMW Archived 5 August 2018 at the Wayback Machine British Superbike.com Retrieved 5 August 2018 http://www.britishsuperbike.com/news/hedger-steps-up-for-the-injured-smrz-at-lloyd-and-jones-bowker-motorrad-bmw/ ↩
"Jakub Smrz". motorcycle-usa.com. Motorcycle USA, LLC. Archived from the original on 23 July 2010. Retrieved 5 July 2010. https://web.archive.org/web/20100723153010/http://www.motorcycle-usa.com/552/Motorcycles/Jakub-Smrz.aspx ↩
"Smrz, B&G to make immediate Aprilia move". crash.net. Crash Media Group. 5 July 2010. Retrieved 5 July 2010. http://www.crash.net/world+superbikes/news/161253/1/smrz_bg_to_make_immediate_aprilia_move.html ↩
"Smrz out-qualifies factory Aprilias". crash.net. Crash Media Group. 31 July 2010. Retrieved 3 August 2010. http://www.crash.net/world+superbikes/news/162108/1/smrz_out-qualifies_factory_aprilias.html ↩