During filming, Seamus Davey-Fitzpatrick was never told that his character was supposed to be the son of the Devil; co-star Julia Stiles has commented that it was because the filmmakers thought "he was too young to understand it, but he was really obedient when John asked him for the Damien face."
The role of Katherine Thorn was originally offered to Rachel Weisz who declined because she was pregnant at the time. Other actresses considered for the part were Laura Linney, Hope Davis and Alicia Witt, before Julia Stiles who finally got the part. Stiles and Mia Farrow were both in a play together, and Stiles suggested to director John Moore that they use Farrow for the role of Mrs. Blaylock (Damien's nurse). Initially Moore didn't think that Farrow would accept the role, but Stiles convinced him she would. Eventually he just rang up Farrow at her home and offered her the part.
The studio originally wanted the film to receive a PG-13 rating but John Moore insisted on an R-rating, suggesting people would "smell a cop-out" if a remake of The Omen (1976) was to receive a family friendly certificate.
The text of the newspaper announcement of Thorn's appointment reads: TOP JOB FOR US PRESIDENT'S GODSON 34 Year old is USA's Youngest Ambassador LONDON - Robert Wade Thorn has been appointed by the White House as the new ambassador to the Court of Saint James. Thorn, at 34 years old, is the youngest appointee in the history of the US. The post became available to Mr. Thorn following the tragic death last month of his predecessor and former boss, US Ambassador to Italy, Mr Stephen Haines. Haines had been named as the new UK Ambassador and was due to take up the post this week when he was killed in a bizarre traffic accident in Rome city center on May 14. Thorn, a Connecticut native, and constant fixture on the Washington DC "rising star" list has often been regarded as a close confidante of the US President's inner circle..." (The text repeats at least three times within the article.)
The opera "Salome" by Richard Strauss, is about the step-daughter and niece of King Herod. Herod, desiring Salome, asks her to do the dance of the seven veils in exchange for her heart's desire. Salome agrees, but after the dance requests the head of John the Baptist on a platter. She receives the head, but Herod, frightened and superstitious, orders Salome to be killed.
At 44min 20secs, the meeting under the "Orange Yard W1" bridge was filmed on the North side of the Charles Bridge in Pague. Exact address for the camera location is 7 Na Kampe, Prague. Llooking to the South.