In the English dub, this movie revealed Ash's mother's first name, Delia, as well as Professor Oak's first name, Samuel.
When Team Rocket appears and start their normal quotes, James and Ash break the fourth wall. James says "Make it double, we're on the big screen" and Ash interrupts by saying "I'll have to catch this on video!"
Patrick Stewart and Ian McKellen were both considered for voicing the role of Lawrence III (A.K.A The Collector).
The collector's real name, Lawrence III, is never once used in the film. It was revealed in promotional materials and the like.
Cards were given out in the theatrical release in the USA. In the first week, a replica of the Ancient Mew card was given out. In the following weeks, cards for legendary birds, Zapdos, Moltres and Articuno were given out.