Career
She made her television debut in 1963 in a small guest role on The Doctors. Shortly thereafter she landed a recurring role on the soap opera Love of Life. She made her film debut starring in the 1966 movie Teenage Gang Debs as Ellie.
The following year she portrayed Penny Wohl in the critically acclaimed independent film David Holzman"s Diary.
The film never got much in the way of theatrical distribution despite having Dietz"s nude scene featured in Life Magazine"s photo spread and in the book of the film. She did not recall if she auditioned for the role of Penny but she added, "it was a fun shoot."
Dietz spent much of the late 1960s and early 1970s appearing in theatre productions.
She notably appeared Office-Broadway as the Young Girl in the premiere of Bruce Jay Friedman"s Steambath at the Truck and Warehouse Theater in 1970. In 1972, she portrayed an androgynous runaway in the premiere of Joyce Carol Oates" Ontological Proof of My Existence.
Her portrayal in the play led to an invitation to do a screen test for The Exorcist.
She was cast in two memorable roles in the film: The Demon (better known as The Face of Death), and the "Possessed Regan" (the Linda Blair character). Foreign this role, Dietz actually only appeared on film for 8–10 seconds. After The Exorcist, Dietz had a highly active career on television during the 1970s, appearing as a guest star on such shows as Planet of the Apes, Korg: 70,000 British Columbia, Barnaby Jones, and Happy Days among others
She also portrayed the recurring role of Linette Waterman in the soap opera The Guiding Light and appeared in the films You Light Up My Life (1977) and Parts: The Clonus Horror (1979).
In 1980, Dietz joined the cast of General Hospital as Sarah Abbott, a role she played for several years. She also appeared as a guest star on Trapper John, Doctor of Medicine (1982) and in the horror film Freeway Maniac (1989).
More recent film credits include Naked in the Cold Sun (1997), Hurricane Festival (1997), Bad Guys (2000), Exorcism (2003), The Mojo Cafe (2004), Neighborhood Watch (2005), Constantine (2005), Karla (2006), Creepshow III (2006), Dog Lover"s Symphony (2006), and Tracing Cowboys (2008). 2009 was a very busy year for Dietz.
She had several films coming out, including Stingy Jack, H2: Halloween 2, See How They Run, The Queen of Screams (2009), Butterfly, Second Coming of Mary, Legend of the Mountain Witch" and the Charles Manson Biopic Charlie Lives: The Movie.
Eileen has been cast in the upcoming thriller Eden Falls(2017). Company-written by Victor Miller, creator of Friday the 13th.