- Completely Different Title: The Brazilian Portuguese title is When Two Women Sin.
- Creator's Favorite Episode: Bergman considered this and Cries and Whispers to be his best works.
- Production Posse: This film represented a passing of the torch for Ingmar Bergman's leading ladies, with Liv Ullmann in the first of ten theatrical films for him, and Bibi Andersson in the eighth of eleven Bergman theatrical films.note Sven Nykvist is also on board as cinematographer.
- Romance on the Set: Ingmar Bergman and Liv Ullmann fell in love during filming. They had a relationship that lasted until 1970 and had a daughter.
- Shrug of God: A notorious example of an open-ended Mind Screw work where the creator refused to explain things. Bergman said he had his own ideas about what Persona meant, but felt it was up to audience to interpret the film, so he never discussed them.
- What Could Have Been: There was a different ending planned. It would have Elisabet recovering from her muteness and going back to her work as an actress. Alma remains on the island and plans to write Elisabet a letter but decides against it. She makes a speech about how she loves being a nurse and decides she'll marry her boyfriend and have children after all. Elsewhere, Elisabet lets out a silent scream.
- Working Title: Cinematography.
- Writing by the Seat of Your Pants: Bergman didn't start filming with a completed screenplay, and changed and added things during production.
- Written by Cast Member: Bibi Andersson rewrote Alma's monologue about the boys on the beach.
Trivia / Persona (1966)