Early 80 's she played in some movies but her big break came with the role of Diane Chambers in the sitcom Cheers. The series had some time to break through but eventually ran eleven seasons and was one of the most popular series of the time.
In 1984 , she was nominated for a Golden Globe for best lead actress for the movie Irreconcilable Differences. She went on to star in some comedies such as The Money Pit with Tom Hanks in 1986, Outrageous Fortune with Bette Midler and Peter Coyote from 1987 and Hello Again with Corbin Bernsen from 1987.
Under much controversy she left the role of Diane Chambers after five seasons at the height of the popularity of the series. The producers of the show even begged her to stay and offered her $ 400,000 but Long refused. Allegedly she could not get along well with some of her colleagues and she wanted television trade it for a film career. In a 2003 interview she said she left for several reasons but the most important was that they wanted to spend more time with her newborn daughter.
Her first post-Cheers project was the film Troop Beverly Hills, where she played a housewife who was leader of the girl guides to distraction to find her separation issues.
In the early 1990s, she played in some movies that were not a commercial success. In 1993 , she returned to Cheers for the last episode. She also starred in the sitcom Good Advice with Treat Williams and Teri Garr,but the show was cancelled after two seasons.
In 1995 she recorded again in the role of Diane Chambers on Frasier, a spin-off of Cheers and also appeared in the re-make of The Brady Bunch Movie that surprisingly became a hit. She also played a year later inA Very Brady Sequel that only a modest success. She would once more in the role of Carol Brady crawling in 2002 for The Brady Bunch in the White House .
After 23 years of marriage asked Tyson in 2004 the separation.