Frances de la TourFrances de la Tour reprises the role of Madame Olympe Maxime (from Harry Potter and the Goblet of Fire) in this film; the character does not appear in the book. She may be a substitute for Viktor Krum (also from the Goblet story), who appeared prominently at the same scene in the book.
Jason IsaacsJason Isaacs originally considered not returning for this film, fearing that his character's arrest and imprisonment at the end of Harry Potter and the Order of the Phoenix would mean very little if any screen time in the finale. Upon meeting J.K. RowlingJ.K. Rowling, he begged to be let out of prison. She told him "You're out. Chapter one." This immediately convinced him to sign on for the film.
Filming the "Seven Harrys" scene was so complex that Daniel RadcliffeDaniel Radcliffe counted over 90 takes for just a single shot.
John HurtJohn Hurt's reprisal as Ollivander marks the longest gap - 9 years - since his previous appearance of the series. Toby JonesToby Jones reprisal as Dobby was second longest, as 8 years.
This time around, Dobby and Kreecher were in most cases played physically on set by their respective voice actors, who the SFX team then had to replace with their CG characters in post-production.
The only [Harry Potter] film Industrial Light & Magic did not provide visual effects for.
Having Bellatrix carve "mudblood" into Hermione's arm during the torture scene was not in the original script, but it was an idea that both Emma WatsonEmma Watson and Helena Bonham CarterHelena Bonham Carter came up with together on the spur of the moment during filming. Filming that scene proved to be very intense for the actors involved (Most of the scene was cut to avoid an R rating in the USA and a 15 rating in the UK). So intense and brutal as it was that Helena Bonham CarterHelena Bonham Carter approached Emma WatsonEmma Watson right afterward to make sure they were still on good terms.
Despite individual billing in end titles and poster billing, John HurtJohn Hurt has fewer than 5 lines.
It had been reported that the film would contain a few scenes of Daniel RadcliffeDaniel Radcliffe in the nude, leading to speculation among fans that the film would earn a more strict rating. This turned out not to be the case, although the scene in which visions of Harry and Hermione kissing appear to try to deter Ron give the illusion that Radcliffe and Emma WatsonEmma Watson are both nude. In reality both actors wore jeans and Watson was provided with a strapless brassiere so she would not have to be completely topless. Director David YatesDavid Yates said that complete nudity was not necessary as the characters would be partially obscured by fog.