She left Ontario after two years to study at St. Peter's College, Oxford, on a year-long Rotary International Ambassadorial Scholarship,[3] though this was not as an admitted member of the university in Statu Pupillari.

The day after filming wrapped on Yanks, Eichhorn flew to Boston to play Gertrude Wentworth in Merchant-Ivory's The Europeans, for which she won a BAFTA nomination for Best Supporting Actress.

Eichhorn made a handful of London television appearances, then moved to Hollywood where she collaborated with actor Treat Williams on her first American film, Why Would I Lie?

Eichhorn's film work at this time included Wildrose and Opposing Force in L.A. and East Lynne, with Martin Shaw, and The Weather in the Streets, with Michael York and Joanna Lumley, for the BBC in London.

She made her New York theatre debut opposite Nathan Lane in The Common Pursuit in 1986, while playing Elizabeth Carlyle on All My Children for a year.

She shot the film Moon 44 for Roland Emmerich in Germany, then began a fruitful association with the Royal Exchange Theatre in Manchester, England, in Alex Finlayson's award-winning Winding the Ball, under the direction of Greg Hersov.

In 1990, Eichhorn made her Broadway debut at the Belasco Theatre in The Speed of Darkness, with Len Cariou, Stephen Lang and Robert Sean Leonard.

In London, Eichhorn worked in theatre (Women of Lockerbie, Enduring Freedom) and television (Spooks, Midsomer Murders, Inspector Morse, Cracker).