When Clerici asks the operator to connect him with Prof. Quadri, the telephone number he gives is the (one-time) telephone number of Bertolucci's idol Jean-Luc Godard. When Quadri answers the phone, Clerici recalls one of his lectures in which Quadri said "The time for reflection is over. Now is the time for action." This is the opening line in Godard's film Le Petit Soldat.
The hospital that Clerici's father is at is actually the Teatro Libera (Free Theater) at the Palazzo dei Congressi in EUR, a massive complex on the outskirts of Rome that was begun as a monument to the Fascist Government. This massive, modernist white marble complex and theater have appeared in several other films and television shows.
The film was in contention for the Golden Bear at the Venice Film Festival. However, a huge controversy over the inclusion of Michael Verhoeven's film O.K. (1970) resulted in the Festival being abandoned and no awards being given out.
Alberto Moravia's novel is told from an omniscient point of view. For the film adaptation, Bernardo Bertolucci chose to tell the story more from the viewpoint of the protagonist, whose memories and feelings are deliberately misleading and unreliable. Bertolucci's non-linear approach to the film's timeline only adds to the film's stream-of-consciousness feeling.