At the age of five, she was given ballet lessons and by nine years old, was introduced to ballroom dancing, immediately falling in love with it. After high school, she graduated from Fordham University but put her academic studies on hold to pursue her ballroom dancing career in the United Kingdom. Karina and her former partner Slavik Kryklyvyy shared tremendous success winning the U.S. Championships and many other world titles and were ranked second in the world in the Latin division. Among her other achievements were Five-time U.S. National Champion, World Trophy Champion and Asian Open Champion
Smirnoff first came on the radar during season three when she swung into a second place finish with partner and later real-life boyfriend, Mario Lopez. Not a bad start for a "DWTS" rookie. The next season, she finished fifth with Billy Ray Cyrus. The two would team up again after their last dance when Smirnoff guest-starred on his hit show, "Hannah Montana." Her subsequent partners for consecutive seasons were boxer Floyd Mayweather, Jr., famed chef Rocco DiSpirito, R&B singer Mario, and billionaire Steve Wozniak. For season nine, she was partnered with boy-bander, Aaron Carter, but not before her well publicized engagement to and subsequent breakup with fellow pro-dancer and her male equivalent in the sex appeal department, Maksim Chmerkovskiy.