Since 1986 she has appeared in a variety of films, many of which were Italian productions. In 2004, she had a starring role in Snakehead Terror, a Canadian film. She played "Karen Oldham" in the television adaptation of Peter Benchley's Amazon (1999). She also had a few minor television roles, including one episode of Wings, and a voice role in an episode of King of the Hill.
In 2006, Alt was honored as Grand Marshal at the German-American Steuben Parade in New York City, the largest celebration of German-American Friendship in the United States. She was greeted by thousands of fans alongside Fifth Avenue. She was a contestant on NBC's 2008 The Celebrity Apprentice, with Donald Trump, competing for her charity, the Tony Alt Memorial Foundation (named for Alt's father), which raises funds for scholarships for young adults to continue their studies. She ended up in third place before being fired, but was brought back for the final task of the show and was chosen by finalist Piers Morgan to help him to become the Celebrity Apprentice. Alt raised a total of $40,000 for her charity.
In September, 2013, Alt joined the Fox News team with her own half-hour Saturday afternoon TV show, A Healthy You & Carol Alt,which covers her own experience and knowledge about wellness and longevity. Each installment ends with a segment called "Ask Carol", in which she answers questions she receives on Facebook and Twitter.