Lt. William 'Bill' Kinderman
Father Joseph Kevin Dyer
James Venamun / The Gemini Killer
Father Damien Karras / Patient X
Father Morning
Dr. Temple
Nurse Allerton
Stedman
Ryan
University President
Sergeant Atkins
Mrs. Clelia
Nurse X
Dr. Freedman
Nurse Keating
Shirley
Mary Kinderman
Father Kanavan
Julie Kinderman
Patient A
Dr. Bruno
Korner Boy
Nurse Merrin
Nurse Blaine
Thomas Kintry
Altar Boy
Mrs. Kintry
Elderly Jesuit
Nurse Bierce
Alice
Counter Attendant
Waitress
Police Sergeant
Second Police Officer
Police Driver
Old Man in Wheelchair
Attendant
Casperelii
Little Old Lady
Dream Blind Man
First Dream Boy (uncredited)
Second Dream Boy (uncredited)
Old Man in Dream (uncredited)
First Dream Woman (uncredited)
Second Dream Woman (uncredited)
Radio Man (uncredited)
Young Girl in Dream (uncredited)
Nurse
Larry King
Everett Koop
Angel of Death
Young Boy in Dream (uncredited)
Mental Patient (uncredited)
Nurse (uncredited)
Satan (voice) (uncredited)
Angel (uncredited)
Student (uncredited)
Hospital Ward Priest (uncredited) (unconfirmed)
John Thompson - Georgetown Hoyas Basketball Coach (uncredited)
Man in Purgatory (uncredited)
Asylum Inmate (uncredited)
Crime Photographer (uncredited)
Penitent (uncredited)
Patient X Possessed