In 2008 Katarzyna Broniatowska competed in her first race at a major international event, the Junior World Championships in Bydgoszcz . Over 1500 meters she was eliminated in the preliminary round. In 2009 she finished eleventh at the Junior European Championships in Novi Sad, Serbia . In 2011 she won the bronze medal over 1500 meters at the U23 European Championships in Ostrava and took sixth place over 800 meters in the final. At the World Student Games in the same year, she took eleventh place for her specialty. In 2013 she won the bronze medal at the European Indoor Championships . At the Universiade in Kazan , Russia , she took seventh place and fifth place with the Polish 4-by-400 relay. At the Francophonie Games, she finished fifth. In 2014 she was eliminated in the preliminary round of the World Indoor Championships in Poland. In 2015 she missed the bronze medal in fourth at the European Indoor Championships in Prague by just under a second. At the European Indoor Championships in Belgrade 2017, she was eliminated over 1500 meters in the qualifying round.