The contact lenses damaged Tim Robbins' eyes. An ophthalmologist has required on set for a few days to supervise because Robbins refused to take them off while shooting.
The story about a nurse named Cora that Josef tells to Hanna is a short-story named "La señorita Cora" by argentinean writer Julio Cortázar from his book "Todos los fuegos el fuego".
Even though they knew when they were cast that their characters had a homosexual romantic relationship, Isabel Coixet said that the actors were really reluctant to kiss when shooting the scene, so she had to filmed it the way you see in the movie.
The oil rig used was the Borgholm Dolphin rig that was docked in Belfast at the time.