She dropped out of college after she was interviewed by a local paper and revealed her famous family background: "One of the drama teachers used the story to illustrate to the class that this crap is what Hollywood's all about, using people's names to get somewhere.

She started modeling and, in 1979, posed nude for the March issue of Playboy magazine, which she called "some kind of rebellion on my part, some way of saying screw you to the family image".

Crosby had a small recurring role in Aaron Spelling's primetime drama, Models Inc, a spin-off from Melrose Place.

She was a guest star on the eighth season of The X-Files for two episodes, in which she plays a doctor who examined Agent Scully's baby.

She starred in Stephen King's Pet Sematary, played the lead role in Dolly Dearest in 1991, and also appeared in Deep Impact and Quentin Tarantino's Jackie Brown.

Initially one of the top-billed characters and featured prominently in episodes such as "The Naked Now" and "Code of Honor", the role of Tasha gradually moved into the background as other members of the ensemble cast became a greater focus of the series.

Crosby also guest-starred in several other TNG episodes, including "Redemption" and "Unification" as Romulan Commander Sela, the half-human, half-Romulan daughter of Tasha Yar, who had been taken prisoner in the past while on board the Enterprise-C. Crosby later reprised the role in the Star Trek: Armada video game, and again in the series finale, "All Good Things...", in which Captain Picard is moving back and forth through time, and encounters Tasha during the events just prior to the pilot episode.

In 2013, Crosby provided voicing for the characters of Tasha Yar and Sela in the Cryptic Studios MMORPG Star Trek Online.

Crosby became the first of a new wave of several Star Trek alumni to return to the roles they originated since Leonard Nimoy's participation at the game's launch in 2010.

In January and February 2010, Crosby performed alongside Gale Harold and ex-model Claudia Mason in Tennessee Williams' Orpheus Descending at Theater in Los Angeles.

Crosby also played the role of widow Margie Curtis in the TV series Bones, season three, episode four, "The Secret in the Soil".