Carillo played on the women's circuit in the 1970s and 1980s being ranked as high as number 33 in the world. In 1977, she won the French Open mixed doubles championship with childhood friend John McEnroe. Knee injuries forced Carillo to retire from competitive tennis.

Once, in a post-match interview during her playing days, Carillo was asked why she had lost. She said, "I blame society."

In 1980, Carillo began working as a reporter for CBS Sports' coverage of the U.S. Open Tennis Championships. In 1986, Carillo joined CBS Sports permanently as a tennis analyst. Later, she joined NBC Sports as an analyst for tennis broadcasts of the French Open and Wimbledon. She also covered tennis for USA and ESPN, and served as a morning host for NBC's coverage of the 2004 Summer Olympics on USA and Bravo.

She is sometimes credited with coining the phrase "Big Babe Tennis" to describe the era in women's tennis dominated by large, powerful players such as Lindsay Davenport and Serena Williams.

During the 2006 Winter Olympics, she co-hosted the critically-acclaimed daily figure skating television program Olympic Ice, on USA Network with co-hosts Scott Hamilton, Dick Button, and Jamie Sale and David Pelletier.

Carillo has written two books: Tennis My Way with Martina Navratilova and Rick Elstein's Tennis Kinetics.

Aside from her commentary duties, Carillo serves as a correspondent for the HBO Sports magazine, Real Sports with Bryant Gumbel.

Carillo lives in Naples, Florida with her two children.