Despite winning several medals in junior categories Chocová's swimming career in adults was marred by problems with her shoulder.

At 2012 European Long Course Championships in Debrecen, Chocová won a bronze medal in non-Olympics distance of 50-metre breaststroke in a time of 31.25, a national record.

The end of the year was more successful for her as she won gold and silver medals at short-course European championships clocking 30.02 and 1:05.50 in 50-metre and 100-metre breaststroke events.

Three weeks later at 2012 World Short Course Championships in Istanbul, Petra Chocová finished 6th and 8th in 50 m and 100 m breaststroke respectively.

She set a new 100-metre breaststroke national record for the Czech Republic in August 2014, completing the course in a time of 1:07.66 at the 2014 European Aquatics Championships in Berlin.