Kuzmina represented Slovakia from December 2008 and won the silver medal two months later in mass start at the 2009 Biathlon World Championships in Pyeongchang. She won a gold medal in the 7.5 km sprint and a silver medal in the 10 km pursuit at the 2010 Winter Olympics in Vancouver, British Columbia, Canada. Kuzmina's victory made her the second Slovak after Ondrej Nepela to win a Winter Olympic gold medal, and the first for independent Slovakia. She won another medal – bronze, at the 2011 Biathlon World Championships in Khanty-Mansiysk. At the 2014 Winter Olympics, she again won the gold medal in the 7.5 km sprint. At the 2018 Winter Olympics, she took silver medals in the pursuit and the individual before taking the gold in the mass start, hitting 19 out of 20 targets to become the first biathlete to win gold medals in three consecutive Games, and tying her as the Slovak sportsperson with the most Olympic golds alongside canoeists Pavol and Peter Hochschorner.