She was born Ingoushka Petrov in Poland to a German father and a Polish Jewish mother. During World War II she and her family were imprisoned in a concentration camp. She survived and in Berlin, Germany in the 1950s met and married an American soldier and ended up living in California. After her marriage failed, she returned to Europe but after a small role in a film, she headed to Hollywood where she worked as a waitress while trying to make a career in the movies. Her natural hair colour is brown, though she frequently has lightened it to blonde.

In the early 1960s Pitt was a member of the prestigious Berliner Ensemble, under the guidance of Bertolt Brecht's widow Helene Weigel. In 1965 she made her film debut in Doctor Zhivago, playing a minor role. In 1968 she co-starred in the low budget science fiction film The Omegans and in the same year played in Where Eagles Dare opposite Richard Burton and Clint Eastwood.

It was her work with Hammer Film Productions that elevated her to cult figure status. She starred in The Vampire Lovers, a film based on Joseph Sheridan Le Fanu's novella Carmilla, and Countess Dracula, a film based on the legends around Countess Elizabeth Báthory. She had a small part, as a librarian, in the cult film The Wicker Man (1973), in which she appeared nude in a bathtub.

Pitt also appeared in the Amicus Horror Anthology film The House That Dripped Blood, a gothic horror film that, along with The Vampire Lovers, marked the first of a string of early 1970s successes for her in that genre.

During the 1980s, Pitt returned to roles in mainstream films and on television but her popularity with horror film buffs saw her in demand for guest appearances at horror conventions and film festivals. Other films Pitt has appeared in outside the horror genre are: Who Dares Wins, (aka The Final Option), Wild Geese 2, Hanna's War etc. Generally cast as a 'baddie', she usually manages to get killed horribly at the end of the final reel. "Being the anti-hero is great - they are always roles you can get your teeth into."

It was at this time that the theatre world also beckoned. Pitt founded her own theatrical touring company and starred in successful productions of Dial M for Murder, Duty Free (aka Don't Bother to Dress), and Woman of Straw. She has also appeared in many TV shows in the UK and USA - Ironside, Dundee and the Calhane, Doctor Who ("The Time Monster", "Warriors of the Deep"), Smiley's People, etc.

Pitt made her return to the big screen in the 2000 production The Asylum. The film starred Colin Baker and Patrick Mower, and was directed by John Stewart. In 2003, Pitt voiced the role of 'Lady Violator' in Renga Media's production Dominator. The film was the UK's first CGI animated film.

After a period of illness, Pitt returned to the screen in 2006 for the Hammer Films-Mario Bava tribute, Sea of Dust. In 1998, Pitt narrated Cradle of Filth's "Cruelty and the Beast" album, although her narration was done strictly in-character as the Countess she portrayed in Countess Dracula.

Pitt's first book, after a number of ill-fated tracts on the plight of the Native Americans, was a novel, Cuckoo Run, a spy story about mistaken identity. "I took it to Cubby Broccoli. It was about a woman called Nina Dalton who is pursued across South America in the mistaken belief that she is a spy. Cubby said it was a female Bond. He was being very kind."

This was followed in 1984 by a novelisation of the Peron era in Argentina, where she lived for a number of years after falling afoul of the establishment in England. "Argentina was a wild frontier country ruled by a berserk military dictatorship at the time. It just suited my mood."