George C. Scott character Lt. William 'Bill' Kinderman
Ed Flanders character Father Joseph Kevin Dyer
Brad Dourif character James Venamun / The Gemini Killer
Jason Miller character Father Damien Karras / Patient X
Nicol Williamson character Father Morning
Scott Wilson character Dr. Temple
Nancy Fish character Nurse Allerton
George DiCenzo character Stedman
Don Gordon character Ryan
Lee Richardson character University President
Grand L. Bush character Sergeant Atkins
Mary Jackson character Mrs. Clelia
Viveca Lindfors character Nurse X
Ken Lerner character Dr. Freedman
Tracy Thorne character Nurse Keating
Barbara Baxley character Shirley
Zohra Lampert character Mary Kinderman
Harry Carey, Jr. character Father Kanavan
Sherrie Wills character Julie Kinderman
Edward Lynch character Patient A
Clifford David character Dr. Bruno
Alex Zuckerman character Korner Boy
Lois Foraker character Nurse Merrin
Tyra Ferrell character Nurse Blaine
James Burgess character Thomas Kintry
Kevin Corrigan character Altar Boy
Peggy Alston character Mrs. Kintry
John Durkin character Elderly Jesuit
Bobby Deren character Nurse Bierce
Jan Neuberger character Alice
Alexis Chieffet character Counter Attendant
Debra Port character Waitress
Walt MacPherson character Police Sergeant
David Dwyer character Second Police Officer
Danny Epper character Police Driver
William Preston character Old Man in Wheelchair
Chuck Kinlaw character Attendant
Demetrios Pappageorge character Casperelii
Nina Hansen character Little Old Lady
Shane Wexel character First Dream Boy (uncredited)
Ryan Paul Amick character Second Dream Boy (uncredited)
John Coe character Old Man in Dream (uncredited)
Jodi Long character First Dream Woman (uncredited)
Kathy Gerber character Second Dream Woman (uncredited)
Samuel L. Jackson character Dream Blind Man (uncredited)
Jan Smook character Radio Man
Amelia Campbell character Young Girl in Dream
Cherie Baron character Nurse
Larry King character Larry King
C. Everett Koop character Everett Koop
Patrick Ewing character Angel of Death
Clinton Brandhagen character Young Boy in Dream (uncredited)
Michael Criscuolo character Mental Patient (uncredited)
Cindy Cullom character Nurse (uncredited)
Colleen Dewhurst character Satan (voice) (uncredited)
Fabio character Angel (uncredited)
Randy Aaron Fink character Student (uncredited)
Jeff Henry character Angel (uncredited)
Patt Noday character Hospital Ward Priest (uncredited) (unconfirmed)
Manley Pope character Angel (uncredited)
Charles Edwin Powell character Patient X Possessed (uncredited)
John Thompson character John Thompson - Georgetown Hoyas Basketball Coach (uncredited)
Michael Tove character Man in Purgatory (uncredited)
Brad Waller character Asylum Inmate (uncredited)
Gary Wheeler character Crime Photographer (uncredited)
Teresa Wright character Penitent (uncredited)
