Born in Lansing, Michigan, he graduated from the University of Michigan in 1947, then studied at École des Beaux Arts in Paris with his wife.
As "Emsh", "Ed Emsh" and sometimes "Emsler", between 1951 and 1979 Emshwiller created covers and interior illustrations for dozens of science fiction paperbacks and magazines, notably for Galaxy and The Magazine of Fantasy & Science Fiction.
In 1964 a Ford Foundation grant allowed Emshwiller to pusue his interest in film. From 1979 to 1990 he served as dean of the School of Film/Video at the California Institute of Arts.
There seems to have been no "typical" Emsh cover. His painterly treatment for the August 1951 Galaxy recalls later work by Leo and Diane Dillon.