Tom Baker as The Doctor

Elisabeth Sladen as Sarah Jane Smith

Philip Madoc as Doctor Solon

Colin Fay as Condo

Michael Spice as Morbius (voice)

Stuart Fell as Morbius Monster

Cynthia Grenville as Maren

Gilly Brown as Ohica

John Scott Martin as Kriz

Jon Pertwee as The Doctor (3) (picture) (uncredited)

Patrick Troughton as The Doctor (2) (picture) (uncredited)

William Hartnell as The Doctor (1) (picture) (uncredited)

George Gallaccio as Morbius Doctor (picture) (uncredited)

Robert Holmes as Morbius Doctor (picture) (uncredited)

Graeme Harper as Morbius Doctor (picture) (uncredited)

Douglas Camfield as Morbius Doctor (picture) (uncredited)

Philip Hinchcliffe as Morbius Doctor (picture) (uncredited)

Christopher Baker as Morbius Doctor (picture) (uncredited)

Robert Banks Stewart as Morbius Doctor (picture) (uncredited)

Christopher Barry as Morbius Doctor (picture) (uncredited)