In 1973, Eggar relocated to the United States, settling in Los Angeles, and appeared first in television, guest starring on episodes of Starsky & Hutch and Columbo, the latter with Peter Falk and Theodore Bikel in the episode "The Bye-Bye Sky High IQ Murder Case". She would go on to star in a number of horror films, including The Dead Are Alive (1972), A Name for Evil (1973), The Uncanny (1977), and David Cronenberg's cult sci-fi film The Brood (1979). In 1980, she filmed the Canadian slasher film Curtains, released in 1983.